bioRxiv Subject Collection: Neuroscience's Journal

Neurophysiology of mismatch negativity generation: a biophysical modeling study
The mismatch negativity, or MMN, is a ubiquitous evoked brain response elicited by any discriminable change of an otherwise regular stimulus sequence. Despite its potential clinical relevance - the MMN is known to be affected by brain state, lesions, and neurologic/psychiatric disorders - and a growing body of animal work, the underlying neurophysiology of the MMN is not well understood. This hinders translation of circuit-level animal findings and mitigates the utility of the MMN as a neurologic/psychiatric biomarker. Here, we used biophysical modeling to examine the neurophysiological basis of the MMN as measured in a canonical auditory oddball paradigm with frequency deviants (i.e., tones whose frequency was shifted slightly with respect to standard tones). The response to standards was successfully modeled by a typical feedforward-followed-by-feedback input sequence. The response to deviants required additional, prolonged input to supragranular layers, consistent with input from the non-lemniscal thalamus. This additional input resulted in downward-going pyramidal-neuron currents in both layer 2/3 (via indirect somatic inhibition) and, critically, layer 5 (via direct apical excitation), which together generated the MMN. The results suggest that current circuit-level models of MMN generation derived from animal models are incomplete, and that further work is required to characterize the underlying neurophysiology of the MMN.

Precision functional imaging in infants using multi-echo fMRI at 7T
Personalized functional brain developmental trajectories can be studied with Precision Functional Mapping (PFM). Our previous work has demonstrated that PFM can be achieved in infants despite rapid brain growth. However, even with extensive data collection (up to 1 hour of fMRI), the reliability and precision of these maps remain lower than those observed in youth and adults - particularly within subcortical structures. In this work we demonstrate the utility of high-field 7T MRI compared to 3T MRI for facilitating PFM in infants. We showcase data from multi-echo fMRI acquisitions in the same infants at both 7T and 3T and demonstrate that 7T imaging in infants is safe and feasible with our subject-specific safety workflow. Moreover, we demonstrate that the use of a higher magnetic field strength affords a spatial resolution more appropriately matched to infants' smaller head and brain sizes, yielding notable improvements in data quality, especially for PFM. The increase in both spatial precision and reliability also suggests that 7T MRI can reduce the amount of data required for PFM. Last, we show how ultra-high field imaging can help us study the development of subcortical-to-cortical connectivity patterns, crucial for understanding brain development during this developmental window. 7T MRI is a promising new avenue for developmental cognitive neuroscience.

Inter- and intra-individual differences in temporal modulation patterns of the β-band sensorimotor rhythm and its relationship to corticomuscular coherence during intermittent voluntary contraction
The {beta}-band sensorimotor rhythm (SMR), recorded using electroencephalography, generally desynchronizes from motor preparation and subsequently synchronizes with electromyogram signals during voluntary contraction, thus forming corticomuscular coherence (CMC). However, it remains unclear how the temporal modulation of {beta}-band SMR varies among individuals, potentially leading to individual differences in CMC. It is also unclear how the nervous system modulates {beta}-band SMR to meet varying task demands within individuals. Here, we explored how temporal modulation patterns of {beta}-band SMR affect CMC from two perspectives: inter-individual differences (Experiment 1), and intra-individual variability depending on task demands (Experiment 2). In Experiment 1, participants repeated a steady-force maintenance task. The degree of {beta}-band SMR modulation (i.e., rebound from desynchronization to synchronization) during contractions varied greatly among individuals and was positively correlated with CMC magnitude. This suggests that even under steady-force maintenance, the motor control strategy used while regulating {beta}-band SMR varies greatly among individuals. In Experiment 2, participants who showed significant CMC in Experiment 1 performed four tasks with varying target trajectories. Even within individuals, the degree of {beta}-band SMR modulation was reduced in parallel with the CMC magnitude as more difficult force adjustment was required. This finding suggests that, when confronted with more challenging task demands, our nervous system reduces the oscillation of SMR and desynchronizes its coupling with muscles. Overall, the way in which our nervous system regulates {beta}-band SMR is assumed to represent a strategy for flexible adaptation to diverse motor environments.

The Road Not Taken: Unsaid Word Alternatives are Represented in the Brain
Human language allows multiple ways to express the same thought, implying that several lexical alternatives may exist in parallel before a single word is spoken or heard. We test the multiple alternatives-co-activation hypothesis by combining high-density ECoG during spontaneous dialogue with behavioral paradigms and ranked next-word predictions from large language models (LLMs). Behaviorally, words that LLMs rank as more likely continuations are recognized faster in a preregistered lexical decision task and produced with shorter inter-word intervals in free speech, indicating graded anticipatory activation of alternatives. Neurally, encoding models reveal that activity in classical language regions (IFG, STG) prior to word onset is predicted by embeddings of multiple top-ranked alternatives, not only by the word ultimately used; critically, mean embeddings that pool the top candidates outperform single-candidate embeddings, and the effect persists with arbitrary (non-semantic) embeddings that control for distributional similarity. Extending beyond a handful of options, encoding strength increases as embeddings are averaged across larger top-k sets, implying that a broad cohort of lexical candidates is simultaneously represented. Finally, models trained in comprehension generalize to production (and vice versa), preserving rank order and suggesting a shared neural code for candidate sets across modalities. Together, these findings provide direct evidence that the brain co-activates unsaid alternatives during natural language use and identify parallel candidate activation as a computational principle common to human comprehension, human production, and artificial language modeling.

Reading ability in both deaf and hearing adults is linked to neural representations of abstract phonology derived from visual speech
Learning to read provides access to life-long educational and vocational opportunities. Some, but not all, deaf children find learning to read challenging, due to reduced access to language, whether spoken or signed. In hearing children, the ability to access and manipulate well-specified, abstract "phonological representations" of spoken language is important for developing strong reading skills. However, the role that phonology plays in deaf children learning to read is much less clear. Positive associations between speechreading (lip reading) and text reading have been observed in deaf and hearing children, and deaf adults, suggesting that speechreading may play a role in reading development, regardless of hearing status. Further support for this hypothesis would be provided by evidence that similar neural representations of phonology are evoked by visual speech and other language forms (auditory speech and text), and that these neural representations are related to reading proficiency. We used fMRI and Representational Similarity Analysis (RSA) to identify shared neural representations of phonology. A group of deaf adult participants (N=22), with a mixture of sign language and spoken language backgrounds and reading abilities, were presented with single lexical items as visual speech and text. Adult hearing participants (N=25) were presented with the same words, but as visual speech and auditory speech. We hypothesised that common neural representations of phonological structure of English words would be found in each group in the superior and middle temporal cortex (STC/MTC) and that these shared representations would be more similar across different language forms in better readers. Our data supported these predictions providing neurobiological evidence of the contribution of visual speech to abstract phonological representations, that relate to reading proficiency, in both deaf and hearing adults.

Neural recordings of continuous speech reveal robust signatures of prediction in second language learners of English
When listening to speech in their native language, speakers use prior context to anticipate upcoming phonemes, words, and concepts, integrating information at the sublexical, lexical, and sentence level. While it has been suggested that late second language learners do not predict to the same extent as native listeners, adequately evaluating this claim requires measurement of predictions at these multiple levels of representation simultaneously in natural speech. We recorded magnetoencephalography (MEG) responses from native Mandarin and Sinhala speakers listening to continuous narrative English speech. We used multivariate temporal response function (mTRF) analysis to investigate whether second language listeners demonstrate the same markers of prediction in neural data as native English speakers listening to the same stimuli. We demonstrate that late second language listeners exhibit strikingly similar responses to native speakers in sensitivity to phoneme surprisal and entropy with respect to sublexical, lexical, and sentence-level context. The few small response differences we observed appear most likely to arise from specific properties of the native languages, rather than general differences between native and second-language listening. These results provide evidence that late second-language listeners indeed leverage prediction in similar ways as native listeners in understanding continuous speech. This suggests that multivariate analyses of neural data from naturalistic listening may be vital in carefully evaluating the differences and similarities in speech prediction across populations.

Head movements integrate with brain signals to guide attention
The human brain is part of a moving body. Yet cognitive neuroscience has long treated body movements as artifacts, leaving unclear how neural computations and overt actions combine to support cognition. Here, we propose that targeted head rotations act as behavioral filters of relevant input under distraction. We show that selective attention is jointly implemented by neural filtering (lateralization of alpha oscillations) and head rotation. In a cued auditory spatial attention task, N = 33 human participants attended to lateral targets or ignored lateral distractors. Neural oscillatory activity, the electrooculogram (EOG), and head movements were recorded using electroencephalography (EEG) and a head-mounted gyroscope. In half of the trials, we purposefully allowed free movements of the head. Listeners exhibited robust patterns of head rotation towards lateral targets, which improved task accuracy by reducing target uncertainty. Note that significant movement residues remained even when head motion was discouraged. Neural filtering, measured as decreased alpha oscillations contralateral to targets and vice versa for distractors, was assessable for conditions with and without head movement permitted but did not relate to task accuracy. Critically, neural and behavioral filters were positively linked on a trial-by-trial and on a between-subject level, with neural filtering preceding behavioral filtering in time. Together, these results underscore that selective attention arises from coordinated brain-body dynamics, highlighting the need to integrate overt movement into mechanistic models of cognition.

Nose-to-Brain Administration of Cannabidiol-Loaded Polymeric Micelles Improves the Core Behavioral Symptoms of Autism Spectrum Disorder
Neurodevelopmental disorders including autism spectrum disorder (ASD) affect 5.9% of the global population. Research shows the potential therapeutic use of cannabidiol (CBD) to treat different neurodevelopmental disorders, including ASD. Intranasal drug delivery (i.n.) is a non-invasive and painless administration route that enhances drug bioavailability in the brain by bypassing the blood-brain barrier. However, i.n. has limited bioavailability due to the low nasal mucosa permeability. Various polymeric nanoparticles have been investigated for i.n. delivery with different successes. In this study, we developed and characterized polymeric micelles of the poly(ethylene oxide)-b-poly(propylene oxide) block copolymer Pluronic F127 loaded with 25% w/w CBD for nose-to-brain delivery in ASD. CBD-loaded polymeric micelles display a hydrodynamic diameter of 41 nm by Intensity and 23 nm by Number, as measured by dynamic light scattering, and showed very good compatibility and permeability in the human nasal septum cell line RPMI 2650, an in vitro model of the nasal epithelium. The accumulation of CBD-loaded polymeric micelles upon i.n. administration to autistic rats is confirmed by bioimaging. The pharmacokinetics of CBD upon i.n. (dose of 5 mg/kg) and oral (15 mg/kg) administration of the loaded polymeric micelles shows a 27.8% increase of the CBD concentration in the brain 20 min of autistic rats after i.n. administration, despite the 3-fold decrease in the dose. Finally, the efficacy of this nanoformulation to improve the core symptoms of ASD is demonstrated in behavioral studies in a rat model of the disorder.

Psychiatric risk implications of adolescent exposure to environmental insecticides: a systematic review of rodent studies
Adolescence is a sensitive period of neurodevelopment marked by remodeling of brain circuits that support cognitive development and emotion and behavior regulation. These maturation processes heighten psychiatric vulnerability to environmental exposures, including to toxicants such as insecticides. Epidemiological studies show widespread adolescent insecticide exposure and increasingly link this with psychiatric outcomes, yet underlying neural mechanisms remain poorly understood. Preclinical studies can clarify these associations and identify insecticide-induced mechanisms that may disrupt neurodevelopment and produce consequent long-term behavioral outcomes. Here, we performed a systematic review of rodent studies following PRISMA guidelines. 50 original articles met inclusion criteria, examining neurotoxic outcomes following insecticide exposure during adolescence (postnatal days 21-60). Outcomes were categorized into four domains: neurocognitive, neuropsychiatric, neurobiological, and general neurotoxicity. Risk of bias was assessed using the SYRCLE Risk of Bias tool. Across studies, insecticide exposure during adolescence led to learning and memory impairments and tended to increase depression relevant behaviors, alter locomotor activity, and produce general neurotoxic effects. Mechanistic findings highlighted disruptions in cholinergic and monoaminergic signaling, oxidative stress, neuroimmune changes, and cell death and other neurodegenerative processes. Together, these findings indicate adolescent insecticide exposure disrupts multiple neural systems with behavioral consequences relevant to adolescent development and psychiatric risk. Future research should model real-world exposures (e.g. dose, timing) to better inform translational understanding of adolescent psychiatric vulnerability. Because many life-long neuropsychiatric disorders emerge in adolescence, identifying how modifiable environmental exposures shape risk offers an opportunity for prevention and intervention strategies to alter the course of disease across the lifespan.

Neuropathological Correlates of Apathy Progression in Alzheimer's Disease and Related Dementias: A Longitudinal NACC Cohort Study
Objective: Apathy is a prevalent and disabling symptom in Alzheimer's disease and related dementias, yet its progression across neuropathological subtypes remains incompletely understood. This cohort study investigates longitudinal changes in apathy and their associations with major neuropathologies using data from the National Alzheimer's Coordinating Center. Methods: We analyzed 1,488 participants with autopsy-confirmed neuropathology and at least two caregiver-reported NPI-Q assessments. Generalized linear mixed models were used to assess associations between apathy and six neuropathologies, Alzheimer's disease (AD), Lewy body disease (LBD), frontotemporal lobar degeneration (FTLD), hippocampal sclerosis (HS), cerebrovascular disease (CVD), and cerebral amyloid angiopathy (CAA). with time modeled as years to death and including interaction terms. Sex stratified analyses were also conducted. All models were adjusted for age at death, sex, and NPI-Q total score excluding apathy. Results: Apathy prevalence increased over time across all pathology groups. FTLD (OR = 2.11, 95% CI: 1.32-3.39) and HS (OR = 2.23, 95% CI: 1.38-3.60) were consistently associated with higher odds of apathy throughout the disease course. No significant interaction effect was observed in any of the neuropathologies. In sex stratified analyses, FTLD (OR=2.58, 95% CI 1.40-4.77), HS (OR=2.48, 95% CI 1.29-4.77), and LBD (OR=1.64, 95% CI 1.03-2.61) were significantly associated with apathy in males, while only HS (OR=2.18, 95% CI 1.06-4.47) remained significant in females. Interpretation: Apathy severity varied by neuropathologies but progressed similarly over time. The elevated burden in FTLD and HS, particularly among males, underscores the importance of stratified approaches to early detection and intervention targeting apathy in ADRDs.

Pharmacological and Physiological Characteristics of Synaptic Transmissions from the Medial Prefrontal Cortex onto Noradrenergic Neurons and Their Presynaptic Neurons in the Mouse Locus Coeruleus
The locus coeruleus (LC) is the primary source of norepinephrine in the brain and is known to modulate brain-wide arousal state. Recent evidence suggests that it also regulates immediate attentional responses by resetting related cortical networks to optimize behavioral outcomes. Cortical regions of high cognitive function, such as the medial prefrontal cortex (mPFC), are theorized to directly influence LC output for the purpose of behavioral regulation. However, the available evidence is insufficient to provide a comprehensive understanding of the underlying mechanisms and properties. To provide further comprehensive data on this issue, we combined ex vivo whole-cell recording with an optogenetic approach to study the synaptic transmission of mPFC inputs to LC neurons, including noradrenergic (NA) neurons and GABAergic neurons presynaptic to them (preLC neurons). Our findings indicate that the mPFC exhibits monosynaptic connections with both NA and GABAergic preLC neurons. These synaptic connections demonstrate cell-type-specific disparities in glutamate release properties. In comparison to those on GABAergic preLC neurons, the mPFC fibers synapsing on LC-NA exhibit a lower release probability (higher paired-pulse ratio) and demonstrate a presynaptic enhancement of glutamate release efficacy during behavior. The features of simultaneous connections onto LC-NA and GABAergic preLC neurons, which exhibit cell-type-specific differences in plastic function of the transmitter release, enable the mPFC to effectively multiplex information to the LC for the adaptive regulation of behavior.

Region-specific proteomic analysis of aging rhesus macaques following chronic glutamate-carboxypeptidase-II (GCPII) inhibition elucidates potential treatment strategies for sporadic Alzheimer's disease
Sporadic Alzheimer's disease (sAD) lacks effective preventive therapies, underscoring the need to target pathogenic drivers. Aberrant calcium signaling is an established early event in sAD pathogenesis that is closely linked to neuroinflammation. Aged rhesus macaques are predominantly APOE-{epsilon}4 homozygotes and naturally exhibit cognitive decline, calcium dysregulation, amyloid deposition, and tau pathology, which allows for a translationally relevant animal model. We previously identified an evolutionarily expanded role for postsynaptic type 3 metabotropic glutamate receptors (mGluR3) in dorsolateral prefrontal and entorhinal cortex, where they regulate cAMP-calcium opening of K+ channels to sustain neuronal firing and working memory. mGluR3 signaling is driven by N-acetylaspartylglutamate (NAAG) and constrained by glutamate carboxypeptidase II (GCPII), whose expression rises with age and inflammation. In prior work, chronic inhibition of GCPII with the orally bioavailable inhibitor 2-(3-mercaptopropyl) pentanedioic acid (2-MPPA) improved neuronal firing, working memory, and reduced pT217Tau pathology in aged macaques. Here, we employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to define the proteomic consequences of chronic 2-MPPA treatment in vulnerable (entorhinal cortex, dorsolateral prefrontal cortex) versus resilient (primary visual cortex) regions. We identified >2,400 proteins across experimental conditions, and label-free quantification revealed region-specific differential expression patterns paralleling known vulnerability gradients in sAD. Gene ontology enrichment of vulnerable regions implicated pathways governing protein deneddylation, amyloid and tau-associated processes, synaptic plasticity, mitochondrial homeostasis, and oxidative stress, revealing putative targets for therapeutic intervention in sAD. These findings demonstrate that GCPII inhibition engages distinct, region-selective molecular programs in the aging primate cortex, consistent with the protection of circuits most vulnerable to sAD. By mapping the proteomic shifts that occur with treatment, we reveal molecular signatures that not only serve as candidate biomarkers but also highlight novel mechanistic pathways contributing to calcium-driven degeneration in sAD. As such, more focused investigations into these pathways of therapeutic interest are warranted, in addition to the analysis of key post-translational modifications and their potential roles in sAD.

Ventromedial prefrontal cortex shields value computations from bodily arousal in decision making
Emotional reactions to norm violations influence how people trade-off selfish interests against social norms, but it remains unknown which brain regions causally contribute to integrating physiological arousal associated with norm violations into the decision process. Here, we provide evidence that the ventromedial prefrontal cortex (vmPFC) causally contributes to decoupling value computations in normative choice from physiological arousal. Excitatory brain stimulation over the vmPFC reduced aversion to disadvantageous inequality in an Ultimatum game and increased post-decision confidence after acceptance of unfair monetary splits. Physiological arousal as measured via heart rate changes was increased in response to splits perceived as unfair. Enhancing vmPFC excitability reduced the sensitivity to unfairness not by directly inhibiting physiological arousal but by blocking its influence on the decision process. This suggests that vmPFC causally moderates how physiological responses to norm violations affect trade-offs between self-interests and norm considerations, highlighting its key role for integrating emotional and cognitive processes in decision making.

Alcohol dependence-induced neuroadaptations in prelimbic KV7 channels contribute to working memory deficits in mice
Chronic alcohol use can cause executive function deficits, such as diminished working memory, which can facilitate excessive alcohol intake and elevate relapse probability even in prolonged withdrawal. Unfortunately, current FDA-approved medications for alcohol use disorder (AUD) are not designed to also treat alcohol-induced cognitive dysfunction. KV7 channels are a class of voltage-gated potassium channels that regulate neuronal excitability and are implicated in cognitive function. KV7 channels are sensitive to acute and chronic alcohol exposure, and positive KV7 channel modulation reduces alcohol intake in high-drinking rodents. The impact of chronic alcohol exposure on KV7 physiology in the prelimbic cortex (PL), a region essential for cognitive function, remains unexplored. To address this, cognitive deficits were measured in male and female mice following the chronic intermittent ethanol (CIE) model of alcohol dependence using a delayed alternation working memory task. After establishing that CIE elicits cognitive deficits regardless of sex, whole-cell patch clamp electrophysiology recordings were performed on distinct PL pyramidal neurons; intratelencephalic (IT neurons) and extratelencephalic (ET neurons) projection neurons to measure KV7 channel mediated M-currents, along with evoked action potential firing following chronic intermittent ethanol (CIE) exposure in male and female mice. CIE exposure led to an increase in intrinsic excitability and a decrease in M-current regardless of sex, which was largely driven by CIE-induced adaptations in IT neurons. These neural adaptations in dependent mice coincided with the emergence of working memory deficits. Microinjections of the KV7 positive modulator retigabine restored working memory function in male and female CIE-exposed mice. Together, these results indicate that chronic alcohol downregulates KV7 function within distinct cortical cell types, and that KV7 modulation may be a promising pharmacological treatment for alcohol induced cognitive impairment.

Modelling the effect of V1a receptor antagonism and its potential therapeutic effect in circadian disorders
Background: The suprachiasmatic nucleus (SCN) is the central circadian clock in mammals, regulating many daily physiological and behavioral rhythms. Dysregulation of the SCN is associated with various circadian disorders, highlighting the potential therapeutic benefits of targeting its neurons and output pathways. Vasopressin signaling is one of the main regulators of the synchronicity and the functional output of the SCN. Methods: We investigated the effect of a single dose (30mg/kg) of the vasopressin V1a receptor (V1aR) antagonist, balovaptan, on resynchronization of locomotor activity rhythms in mice after a 6-hour phase advance of the light-dark cycle. To mechanistically model the effect of V1aR antagonism, we developed a mathematical framework simulating the SCN, its control of circadian biomarkers (melatonin, core body temperature), and the impact of V1aR antagonism. Results: A single administration of the V1a antagonist balovaptan significantly accelerated resynchronization of locomotor activity rhythms to new light-dark cycles. To mechanistically understand this effect, we devised a mathematical model of the SCN that successfully captures this accelerated synchronization of circadian rhythms under V1aR antagonism. Additionally, the model replicates well-established SCN behaviors in both humans and rodents, including the phase response curve triggered by a light pulse at various circadian phases, and the desynchronization of the SCN observed in forced desynchronization experiments. Mechanistically, our model suggests that weakening vasopressin signaling via V1aR antagonism strengthens the SCN's resistance to internal desynchronization. Additionally, our model suggests a strong link between the endogenous period (tau) and the phase of circadian biomarkers, with longer tau values resulting in delayed biomarker rhythms. Importantly, the model predicts that V1aR antagonism induces a phase advance proportional to tau. The model predicts that individuals with longer endogenous periods, who consequently exhibit greater phase delays in their circadian rhythms, could experience more substantial phase advances in response to V1aR antagonism. Discussion: We show that targeting V1aR is enough to cause a faster resynchronization to a new light-dark cycle in the jet lag paradigm and establish a computational framework for investigating its therapeutic potential in circadian rhythm disorders. This framework, adaptable to incorporate pharmacodynamic data, can be used to design clinical trials evaluating V1aR antagonism for treating circadian disorders.

Bayesian multilevel modeling of group and participant level effect sizes: Stronger inter-individual differences in pupil dilation compared to EEG alpha power during aversive conditioning
Aversive conditioning prompts reliable changes in the power of EEG alpha-band oscillations and pupil dilation. Both variables have been used to test hypotheses on the acquisition, generalization, and extinction of conditioned threat. Existing studies have largely relied on trial averages and group-level analyses. Thus, the variability of these physiological markers to aversive learning at the subject level is currently unknown. Comparisons of group-level analyses in prior studies suggest that pupil dilation and EEG-alpha activity capture complementary information. However, to date, no study has directly compared these two markers in terms of their effect sizes at the level of individual participants. The present study employed Bayesian multilevel modeling to quantify the variability of conditioning effect estimates for alpha-band power and pupillometry. Estimates were examined at the group level and at the participant level, across two conditioning paradigms, involving visual and auditory cues. Although the two metrics shared similar effect sizes at the group level, participant-level variability in these effect sizes was substantially higher for pupil-dilation compared to alpha-power, and this finding was replicated across both paradigms. These findings have important implications for clinical and inter-individual difference research which requires both the quantification of effects at the participant-level as well as meaningful variability between-participants that can be linked to relevant differences such as anxiety.

ICAM-5: A Novel Marker for Neuronally Derived Extracellular Vesicles.
Current methods for isolating neuronal-derived extracellular vesicles (NDEVs) from human biofluids lack specificity. In addition, some of the reported markers for NDEV isolation are present as soluble proteins instead of extracellular vesicle (EV) associated proteins. To address the research gap, this study aimed to identify a novel marker for NDEV isolation that is NDEV associate and highly specific to the central nervous system. To achieve this, human cortical neurons were used for isolation of EVs invitro. Mass spectroscopy was performed to screen for potential EV surface markers. This analysis yielded 63 brain specific proteins among which ICAM-5 was selected for further validations in human serum and cerebrospinal fluid (CSF) samples. Our analysis shows that ICAM-5 is present on the surface of NDEVs, colocalizing with standard extracellular vesicle markers like CD-63 and CD-9. We further confirm that NDEVs isolated using ICAM-5 contain neuronal proteins (tau, neuronal specific enolase) but not glial markers. Using ICAM-5 as a NDEV marker, EVs were eluted from human serum samples of with traumatic brain injury. Our results show enhanced levels of ubiquitin C-terminal hydrolase L1 (UCH-L1), a marker of neurological injury, in serum samples from patients with TBI when compared to currently known markers of NDEV. Our findings demonstrate that ICAM-5 is specific EV associated marker for isolating NDEVs from human biofluids that can potentially improve the enrichment of NDEVs from biofluids thereby improving diagnosis and monitoring of neurological conditions.

Structured Neural Variability from Repeated Naturalistic Video Watching Experiences
The brain continuously integrates perception and interpretation processes to navigate dynamic environments. It is often assumed that these processes are invariant to repeated experiences. Here we investigated how neural responses to naturalistic stimuli evolve across multiple viewings using functional magnetic resonance imaging. Twenty participants watched 24 short videos across five separate scanning sessions. Between-subject correlations (BSC) decreased progressively across all brain regions with repeated viewing, indicating increasing individual variability. Within-subject correlations (WSC) consistently exceeded BSC, demonstrating that individuals are more similar to themselves than to others. However, the structure of within-subject variability differed fundamentally between sensory and interpretive regions. Early visual cortex exhibited strong repetition effects, with brain activity becoming increasingly dissimilar with each successive viewing, accompanied by reduced coupling to low-level visual features and decreased anti-correlation with default mode regions. In contrast, ventromedial prefrontal cortex (vmPFC) showed temporal proximity effects, where sessions closer in time exhibited more similar activity patterns regardless of viewing number. This temporal structure in vmPFC aligned with fluctuations in participants' video preferences across sessions. These findings suggest that repeated experiences are never processed identically: sensory systems adapt efficiently to familiar input while interpretive systems continuously reshape meaning based on current internal states.

Interval Timing Shows Selective Enhancement Under Psychosocial Stress: A Cortisol-Mediated Dissociation From Spatial Processing
Acute stress affects cognitive processes, including our perception of time, yet few studies have examined how HPA axis activation specifically modulates time perception. This study provides the first systematic examination of how psychosocial stress influences temporal versus spatial reproduction using the Trier Social Stress Test (TSST), investigating underlying epigenetic mechanisms. Forty-four healthy adults (21 men; mean age 21.96 +/- 3.03) completed temporal and spatial reproduction tasks before and after TSST, with salivary cortisol sampling and DNA methylation analysis of four dopamine-related genes (COMT, DRD2, SLC6A3, TH). The TSST successfully elevated cortisol and state anxiety, confirming effective HPA axis activation. Critically, stress selectively reduced temporal underestimation. Despite their shared neurocognitive mechanisms, spatial processing remained unchanged. This demonstrates that HPA-mediated stress enhances interval timing. Men demonstrated greater stress-induced improvement in temporal accuracy than women, while neither sex showed significant spatial changes, independent of cortisol reactivity differences. The results are discussed in the context of dopaminergic models of temporal processing. Exploratory epigenetic analyses revealed a DRD2 methylation and cortisol response interaction for temporal tasks, with higher methylation associated with greater stress-induced improvement among high cortisol responders. However, sensitivity analysis indicated these interactions were driven by participants with extreme methylation values, limiting the generalizability of epigenetic results. These findings demonstrate that acute psychosocial stress selectively enhances temporal accuracy, potentially through cortisol-dopamine interactions in corticostriatal timing circuits. This work opens avenues for investigating stress-timing mechanisms and cortisol-dopamine interactions in timing circuits, and provides preliminary evidence for epigenetic moderation.

Pupil dilation indexes - but does not causally influence - conscious error detection: a double-blind, placebo-controlled investigation of performance-monitoring using atomoxetine.
Background: Conscious error detection is accompanied by error-related changes in phasic autonomic activity. This autonomic response is diminished in older age - accompanied by impairments in the conscious detection of action errors - i.e., increased "error blindness". Indeed, the degree to which the autonomic response to errors declines across the lifespan is correlated with the increase in error blindness. However, the direction of causality - whether changes in autonomic reactivity are a consequence or cause of increased error blindness - is still debated. In the present study, we experimentally modulated the phasic autonomic response to action errors in healthy older adults while measuring their conscious error detection. Methods: Across two sessions, thirty healthy older adults (60-80 years old) were given the sNRI atomoxetine or placebo in a double-blind fashion. In each session, they performed an anti-saccade task, which is commonly used to test conscious error detection. The autonomic response to errors was measured via changes in pupil dilation. A novelty-oddball task was also employed as a manipulation check. Results: Atomoxetine reduced phasic pupil dilation to both novel stimuli in the novelty-oddball task and to action errors in the anti-saccade task. However, despite this blunting of the phasic autonomic response to errors, there were no significant differences in conscious error awareness between atomoxetine and placebo. Primary task performance was also unaffected. Conclusions: Despite its effects on phasic autonomic activity after errors, atomoxetine had no effect on conscious error detection in healthy older adults. This suggests that phasic autonomic activity is a consequence, rather than a contributing factor, to conscious error awareness. It also suggests that changes to phasic autonomic activity is unlikely to explain increased error blindness in older age.

Timing Is Everything: Temporal Dynamics of BOLD Responses to Naturalistic Features in Movie Watching
Naturalistic stimuli, such as movies and narratives, are increasingly used in cognitive neuroscience to map cognitive and affective processes onto brain activity measured with functional MRI (fMRI). Features extracted from movies span multiple levels, from computational descriptions of visual and auditory input to physiological signals and subjective ratings. However, the temporal alignment between these features and the blood-oxygen-level-dependent (BOLD) response can vary considerably, and the commonly used canonical hemodynamic response function (HRF) with temporal derivatives may not adequately capture these delays. In this study, we analyzed three movie-watching datasets and examined a range of features, including visual luminance and contrast, auditory pitch, a physiological measure of pupil size, and subjective ratings of theory of mind. We performed cross-correlation analyses between feature time series and fMRI responses across the whole brain. Our results show that the canonical HRF captures sensory features well but misaligns with slower signals such as pupil size and subjective ratings. Notably, raw pupil size and subjective ratings exhibited stronger correspondence with delayed hemodynamic responses. Lastly, we showed that video data can be used as continuous input to measure hemodynamic response functions across brain regions. These findings highlight the critical role of temporal alignment in mapping naturalistic features to brain activity. Accounting for feature-specific delays may improve the interpretability and accuracy of fMRI studies using complex, real-world stimuli.

The Effect of Musical Groove on Sensorimotor Network Cortical Dynamics during Active Tapping and Passive Listening
Musical groove, defined as the urge to move in response to rhythmic stimuli, drives spontaneous entrainment and engagement with music. Recent studies have investigated the activation of the sensorimotor network (SMN), focusing on the mu rhythm, an oscillatory activity in the alpha (8-12 Hz) and beta (16-24 Hz) ranges that reflects motor system engagement. While mu modulation differs between passive listening and active movement, it remains unclear whether these responses are shaped by the level of musical groove. Clarifying this relationship is crucial for understanding how neural oscillations transform rhythmic perception into embodied movement and how auditory and motor systems interact to generate the spontaneous urge to move. The present study investigates SMN dynamics by examining mu modulation across two factors: mode of engagement - active motor entrainment (finger tapping) versus passive listening, and groove level - low versus high. Electroencephalography (EEG) recordings were used to assess SMN activity, with a focus on mu rhythm modulation in the alpha and beta frequency bands. Channel and cluster-based EEG analyses revealed stronger mu suppression during active tapping compared to passive listening, as well as an effect of musical groove. Self-reported groove ratings were not affected by the tapping task. Together, these findings highlight the modulation of the mu rhythm in the SMN, describing distinctive patterns of neural engagement during the experience of musical groove.

iPSC derived MSC secretome activates distinct neuroprotective pathways in a preclinical model of Parkinsons disease
Parkinsons disease (PD) is characterized by a progressive loss of dopaminergic neurons, which current therapies fail to address. Mesenchymal stem cells (MSCs) secretome holds promising therapeutic potential; however, the gold standard source - bone marrow (BM) - face scalability limitations. Induced pluripotent stem cells (iPSCs)-derived MSCs (iMSCs) are a rejuvenated and clinically attractive source, yet the effects of their secretome have not been studied in PD. Here, we directly compare the effects of BM-MSCs and iMSCs secretome in a 6-OHDA rat model. Despite few differences in secretome composition, both improved motor function and partially ameliorated anhedonia, but only iMSCs secretome significantly preserved dopaminergic neurons. Proteomic analysis revealed that BM-MSCs secretome activates antioxidant and proteostasis pathways, whereas iMSCs secretome activate broader pro-survival and regenerative pathways, including NRF2-mediated oxidative stress response and mTOR. In addition, iMSC-secretome treatment modulated glutamatergic and GABAergic neurotransmission, suggesting restoration of synaptic homeostasis beyond dopaminergic preservation. These findings demonstrate that iMSCs secretome exerts robust neuroprotective effects and shed light on the mechanisms underlying this scalable and clinically translatable therapy for PD.

Movement Effort does not alter the Planning Horizon of Sequential Reaching Movements
Everyday tasks often involve multiple reaching movements in a sequence, where the choices made for one movement also affect the conditions for subsequent movements. Previous research indicates that humans are capable of planning ahead to optimize such sequences. Here, we ask whether increasing the resistance to movement prompts participants to plan even further ahead to reduce overall movement effort. Participants (n=28) were shown 14 targets that varied in size, value and location, and were instructed to accumulate as many points as possible. To collect each target, they reached while holding the handle of a robotic manipulandum that applied a resistive force. We analyzed their target choices using a planning model that takes into account the size, value and distance of several future targets. We expected that, as resistance -- and therefore the effort required to move between two targets -- increased, participants would plan further ahead to minimize total movement distance. Results show that participants typically planned 2-4 targets ahead. However, increasing resistance did not significantly affect the planning horizon. We conclude that movement effort is not a primary constraint on the planning horizon in sequential reaching movements.

Synergy mediates Long-Range Correlations in the Visual Cortex Near Criticality
Long-range correlations are a key signature of systems operating near criticality, indicating spatially-extended interactions across large distances. These extended dependencies underlie other emergent properties of critical dynamics, such as high susceptibility and multi-scale coordination. In the brain, along with other signatures of criticality, long-range correlations have been observed across various spatial scales, suggesting that the brain may operate near a critical point to optimise information processing and adaptability. However, the mechanisms underlying these long-range correlations remain poorly understood. Here, we investigate the role of synergistic interactions in mediating long-range correlations in the visual cortex of awake mice. We leverage recent advances in mesoscale two-photon calcium imaging to analyse the activity of thousands of neurons across a wide field of view, allowing us to confirm the presence of long-range correlations at the level of neuronal populations. By applying the Partial Information Decomposition (PID) framework, we decompose the correlations into synergistic and redundant information interactions. Our results reveal that the increase in long-range correlations during visual stimulation is accompanied by a significant increase in synergistic rather than redundant interactions among neurons. Furthermore, we analyse a combined network formed by the union of synergistic and redundant interaction networks, and find that both types of interactions complement each other to facilitate efficient information processing across long distances. This complementarity is further enhanced during the visual stimulation. These findings provide new insights into the computational mechanisms that give rise to long-range correlations in neural systems and highlight the importance of considering different types of information interactions in understanding correlations in the brain.

Lower engagement of cognitive control, attention, modulation networks and lower creativity in children while using ChatGPT: an fMRI study
Generative AI can scaffold idea generation, but how it engages control, attention, and memory systems in the developing versus mature brain, and how this relates to creativity, remains unclear. We compared 6-7-year-old (N = 15) children and adults (N = 16) during a naturalistic 5-minute co-creative dialogue with ChatGPT using the same prompt, in-scanner conversation, undergoing functional MRI scanning and their dialogues were recorded. Functional connectivity (Fisher's z) was computed within and between seven large-scale networks: cingulo-opercular, default mode (DMN), memory retrieval, frontoparietal (FP), salience, ventral attention (VAN), and dorsal attention (DAN). Creativity scores, assessed outside of the scanner, did not differ between groups. Adults showed stronger within-network connectivity in control/attention systems, most robustly in FP, with additional effects in salience and DAN. Adults also exhibited greater cross-network integration, particularly FP-salience and FP-DAN couplings, alongside broader adult-greater effects among memory- and attention-related pairs. During a co-creative AI-assisted conversation, children exhibit a less coherent and integrated control-attention-memory architecture than adults. The combination of similar creativity scores with divergent neural profiles suggests that developmental differences in the implementation of creative cognition may be more pronounced than baseline capacity. Our findings highlight FP-centric pathways and their salience-gated interactions as candidate substrates by which creativity supports goal-directed co-creative dialogue with AI.

Electrophysiological profiling of exocytosis during early-stage development of the zebrafish lateral line
Hair cells of the zebrafish lateral line have proven to be a good model for studying hair cell function in a system that is easily genetically manipulated, rapidly develops and is experimentally accessible. However, characterization of potential developmental changes, and possible differences along lateral line position are lacking. Here, we used in vivo patch clamp to investigate the electrophysiological and exocytic properties of neuromast hair cells over early development across body location. Long depolarizations led to steady increases in membrane capacitance, presumably due to exocytosis of vesicles localized to ribbon synapses. The magnitude and kinetics of capacitance changes did not vary significantly across the L1 to L6 position of neuromasts along lateral line, but the magnitudes were found to be significantly smaller in hair cells found in the tail region across all developmental time points. For each region, we found no significant changes in capacitance responses between 3 and 7 days after fertilization. Hair cell capacitance responses were greatly reduced in animals injected with CRISPR/Cas9 with gRNAs targeted to otoferlin b. These results confirm the essential role of otoferlin b in neuromast hair cell function, and they establish the fidelity of CRISPR/Cas9 to rapidly mediate genetic removal of critical genes to study their impact on synaptic release.

Distinct Effects of Aging and Klotho Deletion on the Choroid Plexus
Klotho (Kl) is an anti-aging protein primarily produced in the kidney and the choroid plexus (CP, where it regulates cerebrospinal fluid composition and exerts neuroprotective effects. Here, we investigated the age-dependent consequences of a CP-specific Kl deletion on CP structure and function using mice lacking KL exclusively in CP epithelial cells (Kl{Delta}CP). In control mice, aging markedly disrupted CP architecture and cilia organization both in the lateral (LV-CP) and fourth ventricle (FV-CP). While CP-specific Kl deletion alone caused no major structural changes it induced region- and age-dependent calcification: FV-CP calcification increased in both aged and young Kl{Delta}CP mice, whereas LV-CP calcification emerged only in older Kl{Delta}CP mice. Proteomic analysis of the CP and hippocampus revealed mild molecular alterations, suggesting compensatory mechanisms that preserve structural and functional stability despite calcium dysregulation. Consistently, Kl{Delta}CP mice exhibited no significant behavioral or cognitive deficits. Overall, Kl deficiency sensitizes the CP to age-related calcification prior to overt structural decline, revealing a region-specific and functional link between Klotho, calcium imbalance, and brain aging.

Restoring signatures of consciousness by thalamic stimulation in a whole-brain model of an anesthetized nonhuman primate
Treatment options for Disorders of Consciousness (DoC) are limited due to insufficient understanding of the underlying neurobiological mechanisms. Two primary strategies for characterizing DoC and assessing treatment efficacy are in vivo experiments with animal models, and in silico computational models. We combined both approaches by creating a whole-brain model tailored to the experimental functional magnetic resonance imaging (fMRI) data of a single anesthetized macaque. It was previously reported in an in vivo experiment that anesthesia-induced loss of consciousness was partially reversed by specific electrical stimulation of the thalamic central nuclei. The in silico model reproduced the brain dynamics underlying the restoration of consciousness, providing a potential explanation for the transition between these brain states as continuous trajectories unfolding in a low-dimensional space. Our results demonstrate that whole-brain computational models reproduce the spatiotemporal properties of fMRI recordings during loss of consciousness and during its recovery induced by electrical stimulation, enabling computational exploration of perturbation-based interventions to potentially personalize treatment and aid recovery of consciousness in DoC patients.

Restraint Stress Prolongs Diestrus Phase of Mouse Estrous Cycle
Globally, stress levels among women of reproductive age are rising, while fertility rates continue to decline. Despite this correlation, a causal link between stress and reduced fertility remains unclear. Experimental studies have shown that severe and chronic stress can disrupt reproductive function, but the effects of mild stress, more representative of the daily stress experienced by most women, are still poorly understood. This study aims to identify how mild stress affects the mouse estrous cycle. Nineteen mice were vaginally lavaged daily one week before stress, during 3-day stress, and one week after stress. The mild stress paradigm consisted of two hours of repeated restraint stress each day for three days. Restraint stress disrupted the estrous cycle causing a longer cycle length in stressed mice, characterized by an extended duration in the diestrus phase. These findings suggest that even moderate stress perturbs normal reproductive cycling, potentially contributing to reduced fertility. This work highlights the need to further explore how everyday stressors may subtly impair reproductive health.

Inhibitory Motifs Quench Synchrony Induced by Excitatory Motifs in Biological Neuronal Networks
The connectivity in biological neuronal networks is known to deviate significantly from the random network (Erdos-Renyi) model. Specifically, di-synaptic motifs like reciprocal, convergent, divergent, and chain are found to be either over-represented or under-represented in certain brain regions. Over-representation of such motifs among excitatory neurons is known to induce synchrony. However, cortical activity is typically asynchronous. Thus, it remains unclear how synchrony induced by excitatory motifs may be reduced to physiological levels. To address this question, we systematically vary the prevalence of these four motifs in an Excitatory-Inhibitory (EI) network. We found that over-representation of chain and convergent motifs in the excitatory population led to increased firing rates and greater synchrony. However, this excess synchrony was quenched when we introduced the same type of motifs among inhibitory neurons. Because of the overabundance of motifs, some inhibitory neurons received fewer recurrent inhibitory inputs. Such weakly coupled neurons were primarily driven by uncorrelated external inputs, and therefore, these neurons exerted stronger inhibition on excitatory neurons and reduced both synchrony and firing rates. Thus, we also provide a new mechanism by which synchrony can be controlled in excitatory-inhibitory networks. We predict that the same kind of di-synaptic motifs should be present in both excitatory and inhibitory neurons.

The Cortical Temporal Axis: MEG-Based Cross-Frequency Gradients with Biological Anchors
Neural oscillations have long been used to characterize the temporal dynamics of individual brain regions, yet a parsimonious, system level representation that integrates multi rhythmic activity has been lacking. Using source localized resting state magnetoencephalography (MEG) data, we computed regional power spectra and assessed spectral similarity, then applied diffusion map embedding to construct cross frequency neurophysiological gradients that place whole brain oscillations within a unified, low dimensional coordinate system. We found the first three gradients accounted for over 40% of the variance, remained stable across individuals, and aligned with established functional, structural, and geometric cortical axes. Computational modeling showed that these gradients reflect local excitation inhibition balance, while multimodal analyses revealed strong associations with neurotransmitter receptor distributions, cytoarchitecture, and cell type specific gene expression. Lifespan analyses further demonstrated systematic gradient reorganization, with distinct cognitive mappings onto functions such as language, memory, and multisensory integration. Clinically, Parkinson's disease patients displayed disrupted gradients, particularly in regions linked to language and social cognition. Finally, these gradient patterns exhibited high test retest reliability. These findings establish MEG derived neurophysiological gradients as robust, low dimensional representations of cortical organization, offering a biologically grounded framework for studying brain aging and disease.

Peripheral Nerve Transection Predominantly Drives Sympathetic Nerve Sprouting in Mouse Dorsal Root Ganglia
Sympathetic sprouting in dorsal root ganglia (DRG) is a feature of sympathetically maintained pain (SMP) following peripheral nerve injury, yet the factors determining its occurrence remain unclear. Here, we compare transection and crush injury models to determine if injury type or site influence sympathetic remodeling and pain. Using TH-IR immunostaining and Phox2b reporter mice to selectively label sympathetic fibers, we found that an L5 spinal nerve transection (SpNT) triggered robust sympathetic fiber sprouting and elevated norepinephrine (NE) levels in the DRG, correlating with a mechanical hypersensitivity reversed by chemical sympathectomy. In contrast, a partial sciatic nerve crush injury (PCI) produced long-lasting mechanical hypersensitivity without sympathetic sprouting or NE elevation and was unaffected by sympathectomy. Importantly, sympathetic sprouting was consistently more pronounced after transection injuries at both spinal and sciatic nerve sites, suggesting that injury type, rather than location, is a dominant factor shaping sympathetic remodeling. These findings establish nerve transection as a key driver of sympathetic sprouting and SMP, whereas crush-induced pain likely involves distinct non-sympathetic mechanisms. This distinction has important implications for pain subtype identification and treatment strategies.

Short-term microglia depletion via CSF-1R inhibition promotes functional network reorganization and motor recovery after cortical ischemia
BACKGROUND: Pharmacological options to promote long-term rehabilitation after stroke remain limited. Microglia play a complex role in post-stroke pathology, contributing both to repair and secondary injury. How short-term depletion during the subacute phase affects functional recovery remains unknown. METHODS: Wild-type mice were trained in a skilled reaching task and underwent permanent distal medial cerebral artery occlusion or sham intervention. Mice received either a colony-stimulating factor 1 receptor inhibitor or vehicle treatment between days 3 and 7 post-stroke to deplete microglia. Fine motor performance was assessed behaviorally while bilateral cortical activity was recorded longitudinally through epidural electrocorticography. RESULTS: Microglia depletion did not affect infarct size but resulted in near-complete restoration of fine motor function by day 7, coinciding with maximal microglial depletion. Recovery of fine motor function was accompanied by significant functional connectivity changes in bilateral sensorimotor networks, including increased beta-band connectivity in the ipsilesional motor cortex, which correlated with contralateral fine motor improvement. After microglial repopulation, cells showed altered morphology and gene expression profiles. CONCLUSIONS: Transient microglial modulation during the subacute phase after stroke promotes cortical network reorganization and motor recovery, highlighting a potential time window for future translational studies.

Investigating the Role of Exosome-associated Human Endogenous Retroviruses as Biomarkers in Motor Neuron Disease
Human endogenous retrovirus K (HERV K) reactivation is increasingly implicated in amyotrophic lateral sclerosis (ALS), with ongoing clinical trials investigating antiretroviral therapies. However, there is a limited understanding of how HERV-K is trafficked in peripheral biofluids, and the role of exosomes, which are nano sized extracellular vesicles, in this process remains largely unexplored. Exosomes offer a stable and cell-specific cargo reservoir that may reflect central pathogenic processes and serve as a minimally invasive biomarker source. In this study, we isolated plasma-derived exosomes from ALS patients (n = 21) and healthy controls (n = 16), and quantified exosomal HERV-K gag, env, and pol transcript levels using SYBR Green qPCR with RNase treatment and normalization to both traditional and exosome enriched reference genes. HERV K pol expression was significantly elevated in ALS, with fold-changes ranging from 1.59 to 1.85 (P = 0.037 to 0.051). env and gag also showed increased expression, though with greater variability. Normalization to the exosome-specific gene SOD2 provided the most consistent signal. A trend toward higher pol expression in bulbar-onset ALS was observed. These findings suggest that exosomal HERV-K transcripts, particularly pol, could serve as accessible biomarkers for patient stratification and treatment monitoring in HERV K targeted ALS trials. This work establishes a proof-of-concept for using exosomal cargo to track endogenous retroviral activity in neurodegeneration, supporting further investigation of liquid biopsy approaches in ALS precision medicine.

A Distinct Subpopulation of Extended Amygdala Neurons Drives Food Intake
Background: Neurons in the oval subnucleus of the bed nucleus of the stria terminalis (ovBNST) integrate stress and reward signals to regulate motivated behaviors, including food consumption. However, the contribution of specific ovBNST neuronal subpopulations remains poorly understood. Here, we investigated vasoactive intestinal peptide receptor 2 (Vipr2) expressing ovBNST neurons using chemogenetics, immunohistochemistry, and viral circuit mapping. Methods and Results: Using stimulatory hM3Dq designer receptors exclusively activated by designer drugs (DREADDs), we found that chemogenetic activation of ovBNST Vipr2 neurons significantly increased food intake. We then quantified cFos activation in Vipr2-tdTomato reporter mice following several unique feeding-related manipulations, finding that food restriction (FR) robustly activated ovBNST Vipr2 neurons. Further analysis revealed decreased vasoactive intestinal peptide (VIP) innervation of the ovBNST following FR, in which reduced VIP expression was significantly associated with greater ovBNST Vipr2 cFos activation. Given previous reports of reduced food intake following stimulation of ovBNST neurons expressing protein kinase C delta (PKC{delta}), we used immunostaining to uncover that Vipr2 and PKC{delta} mark largely non-overlapping ovBNST neuronal subpopulations, aligning with their opposing effects on food intake. Finally, Cre-dependent anterograde viral tracing revealed that ovBNST Vipr2 neurons project prominently to the parasubthalamic nucleus (PSTN) and paraventricular nucleus of the hypothalamus (PVN), two feeding-related regions. Conclusions: Together, these results identify ovBNST Vipr2 neurons as a functionally distinct BNST subpopulation that promotes feeding, is activated by food restriction, and links ovBNST neuropeptide signaling to hypothalamic feeding centers.

FOODEEG: An open dataset of human electroencephalographic and behavioural responses to food images
Investigating the neurocognitive mechanisms underlying food choices has the potential to advance our understanding of eating behaviour and inform health-targeted interventions and policy. Large, publicly available neural and behavioural datasets can enable new discoveries and targeted hypothesis tests, yet no such datasets are currently available. We present the FOODEEG dataset containing electroencephalographic (EEG) responses to a diverse array of food images, as well as behavioural measures of food cognition (food categorisation task, food go/no-go task, and food choice task responses), collected from 117 participants. We also provide normative ratings for the food image stimuli with respect to 22 food attributes, including nutritive, hedonic and taste properties, familiarity, and elicited emotions. Our dataset also includes questionnaire-based measures of participants' food motivations, dietary styles, and general motivational tendencies. In the validation analyses, we demonstrate that early food-evoked EEG responses in our dataset are consistent with observations in previous work. The FOODEEG dataset will be valuable for accelerating research into the neural substrates of visual food processing, dietary decisions, and individual differences.

Dissecting mammalian cortical circuit development at single-cell resolution using inducible barcoded rabies virus
Highly organized circuits of connected neurons enable diverse brain functions. Improper development of these circuits is associated with neurodevelopmental disorders, and understanding how circuits are formed is crucial for unraveling the mechanisms of these diseases. We currently have an incomplete picture of how specific brain circuits develop and how they are affected in disease, because we lack methods to study them at scale and with single-cell resolution. Monosynaptic rabies tracing is the gold standard method to study circuit architecture. However, it suffers from cellular toxicity, low throughput, lack of control over the timing of labeling, and the inability to access the molecular profiles of individual neurons. To address these issues, we developed an inducible barcoded rabies virus (ibRV) to enable temporal-controlled labeling of synaptic circuits followed by high-throughput single-cell genomics readout. ibRV allows for dissecting neuronal circuit changes over time at single-cell and spatial resolution. We applied ibRV to study the development of specific mouse cortical circuits during late prenatal and postnatal life using single-cell genomics and unbiased spatial transcriptomics as readouts. We characterized and quantified developmental connectivity patterns and molecular cascades that underlie their formation. Additionally, we constructed functional in silico circuit models that enable interrogation of circuit function and dysfunction at specific developmental stages. Our study provides novel tools for circuit analysis and can provide new insights into the mechanisms of mammalian brain development.

The Earlier You Know, the Smoother You Act
Intercepting a moving object with our hands requires that the moving object and the hand come into contact at some point along the object's trajectory. Hand movement must, therefore, be planned in advance so that the hand reaches a chosen spatial location along this trajectory at the correct moment in time. To enable such anticipatory behavior, the object's trajectory must be predicted based on sensory information collected before movement planning is concluded. Early completion of planning would allow for a smooth and economical movement; however, it also requires sufficiently accurate information about the object's movement to be available earlier. We investigate interception in the context of a complex, naturalistic motor task, toss juggling, to understand the extent to which proprioceptive and tactile information influence anticipatory movements of the catching hand. In our study, we compared solo juggling, where the efferent, tactile and proprioceptive information from the throwing hand is available during catch planning, with dyadic juggling, a functionally ''deafferented'' condition where no such information is available because the ball has been thrown by another person. Our results indicate that when internal and tactile information from the toss is absent, anticipatory behavior is greatly reduced. Experienced jugglers seem to rely more strongly on internal information than vision, allowing earlier planning and lower target uncertainty. In the dyadic condition, when internal information is absent, trajectory planning is delayed, leading to greater target uncertainty.

Astrocytic FABP5 drives non-cell-autonomous oligodendrocyte injury in multiple system atrophy by promoting TNF signaling and ferroptotic stress
Multiple system atrophy (MSA) is a fatal -synucleinopathy characterized by progressive parkinsonism, cerebellar and autonomic dysfunction. Currently, the mechanisms driving cerebellar white matter neuroinflammation and degeneration in MSA are poorly understood. Here, we identified fatty acid-binding protein 5 (FABP5) as a key factor regulating cerebellar inflammation in MSA pathogenesis in a detailed study of human, mouse and cultured astrocytes. Firstly, transcriptomic profiling of human MSA cerebellar white matter revealed activation of pro-inflammatory and ferroptotic pathways, with FABP5 identified as a key pathway component that is upregulated. We confirmed that FABP5 is upregulated in reactive astrocytes in the PLP--syn transgenic mouse model, also in LPS-treated primary astrocytes. Fabp5 silencing suppressed TNF signaling, mitigated ferroptosis, and restored mitochondrial function. These findings suggest astrocytic FABP5 as a central intracellular regulator linking glial inflammation, ferroptosis, and mitochondrial injury. Overall, this mechanism suggests that FABP5 drives pathology mediated by astrocytes oligodendroglia in MSA, therefore representing a novel and promising therapeutic target.

QuNex Recipes: Executable, Human-Readable Workflows for Reproducible Neuroimaging Research
Preprocessing and analysis of neuroimaging data are technically demanding, often requiring a combination of multiple software tools, modality-specific pipelines, and extensive parameter tuning to match dataset characteristics. These complexities make it difficult to document workflows in sufficient detail to ensure complete transparency and reproducibility. To address these challenges, we introduce QuNex recipes, a framework for defining and executing complete neuroimaging workflows -- encompassing data onboarding, preprocessing, and analysis -- in a transparent, machine- and human-readable format. Recipes are implemented as an integrated feature of the Quantitative Neuroimaging Environment & Toolbox (QuNex), a containerized, open-source platform for end-to-end multimodal and multi-species neuroimaging processing. The recipes framework enables seamless integration of QuNex commands with custom scripts and external tools, capturing every processing step and parameter setting. A fully reproducible study can thus be shared and replicated by providing only (a) the QuNex version used, (b) the recipe file, and (c) the data. This approach standardizes workflow specification, enhances transparency, and enables one-command replication of complex neuroimaging analyses. By providing a standardized way to describe and share workflows, recipes facilitate open exchange of best practices and reproducible methods within the neuroimaging community.

Activation of IRF7/ISG15 axis in microglia inhibits NLRP3 Expression and Improves the Prognosis of Ischemia/Reperfusion in Mice
Ischemic stroke is a leading cause of disability and mortality, with neuroinflammation playing a key role in post-stroke injury. The molecular mechanisms remain incompletely defined. This study explored the functions of IRF7 and its downstream target ISG15 in stroke-associated neuroinflammation and prognosis of ischemic stroke. Bioinformatic analysis of transcriptomic datasets from microglia and ischemic brain tissues identified both molecules as hub genes. Their expression was validated in a mouse transient middle cerebral artery occlusion (tMCAO) model and in microglial cultures exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). The effects of these molecules were assessed using siRNA knockdown, conditioned media assays with SY5Y neuronal cells, in vivo overexpression of ISG15, histological and functional assessments. Both IRF7 and ISG15 were significantly upregulated after stroke. IRF7 knockdown reduced ISG15 expression, whereas ISG15 knockdown did not affect IRF7, suggesting a unidirectional regulatory relationship. Conditioned media from microglia treated with siIRF7 or siISG15 increased SY5Y cell mortality, with a stronger effect in the siISG15 group, highlighting neuroprotective role of ISG15. ISG15 knockdown also enhanced microglial migration. Conversely, microglial ISG15 overexpression in vivo promoted a shift toward reduced neuroinflammation, improved neuronal survival, and enhanced functional recovery. Mechanistically, ISG15 stabilized NLRP3 protein but more strongly decreased its mRNA stability through accelerated degradation. These findings demonstrate that the activation of IRF7/ISG15 axis in microglia inhibits NLRP3 Expression and improve the prognosis of ischemia/reperfusion in mice, with ISG15 exerting stronger neuroprotective effects. Targeting microglial ISG15 may offer a promising therapeutic strategy for ischemic stroke.

A human forebrain organoid model phenocopies dysregulated RNA and protein homeostasis in ALS/FTD-associated TDP-43 proteinopathies
Background TAR DNA-binding protein 43 (TDP-43) proteinopathy is a central hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), yet current experimental models fail to reproduce the full pathological spectrum without external stress or TDP-43 overexpression. This study aims to establish a human induced pluripotent stem cells (iPSC)-derived system that spontaneously manifests TDP-43 pathology driven by an ALS-associated TDP-43 mutation. Methods We generated forebrain 3-D organoid cultures from iPSC carrying the TDP-43 K181E patient mutation. Single-cell RNA sequencing was used to define transcriptional alterations across cell types, and enhanced crosslinking immunoprecipitation (eCLIP) was applied to examine the global RNA binding and splicing defects in mutant organoids. We further used immunostaining, RT-PCR and biochemical assays to confirm TDP-43 proteinopathy and validate findings from the multi-omics analyses. Results The TDP-43 K181E organoids recapitulated key disease features, including cytoplasmic p-TDP-43 accumulation, RNA dysregulation, and cryptic exon inclusion. Single-cell analysis revealed a population of immature neurons with enhanced neuroinflammation and altered translation capacity. Comparative transcriptomics showed that the ALS mutation-induced transcriptional changes strongly overlap with those in ALS patient-derived brains. eCLIP analysis showed that mutant TDP-43 exhibited altered RNA-binding specificity, resulting in widespread RNA mis-splicing and cryptic exon inclusion. RT-PCR confirmed PRDM2, a gene regulating cell senescence, is mis-spliced in mutant cells. These defects collectively disrupt neuronal homeostasis and cell-cell communications. Conclusions Our iPSC-derived forebrain organoid model displays spontaneous TDP-43 proteinopathies and associated molecular dysfunctions without artificial manipulation. The model offers a robust platform for dissecting the mechanisms of TDP-43-mediated neurodegeneration and advancing therapeutic discovery in ALS and FTD.

Dissociable neural substrates of integration and segregation in exogenous attention
The integration-segregation theory proposes that early facilitation and later inhibition (i.e., inhibition of return, IOR) in exogenous attention arise from the competition between cue-target event integration and segregation. Although widely supported behaviorally, the theory lacked direct neural evidence. Here, we used event-related fMRI with an optimized cue-target paradigm to test this account. Cued targets elicited stronger activation in the frontoparietal attention networks, including the bilateral frontal eye field (FEF) and intraparietal sulcus (IPS), right temporoparietal junction (TPJ), and left dorsal anterior cingulate cortex (dACC), consistent with the notion of attentional demand of reactivating the cue-initiated representations for integration. In contrast, uncued targets engaged the medial temporal cortex, particularly the bilateral parahippocampal gyrus (PHG) and superior temporal gyrus (STG), reflecting the segregation processes associated with new object-file creation and novelty encoding. These dissociable activations provide the first direct neuroimaging evidence for the integration-segregation theory. Moreover, we observed neural interactions between IOR and cognitive conflict, suggesting a potential modulation of conflict processing by attentional orienting. Taken together, these findings provide new insights into exogenous attention by clarifying the neural underpinnings of integration and segregation and uncovering the interaction between spatial orienting and conflict processing.