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Пишет bioRxiv Subject Collection: Neuroscience (![[info]](http://lj.rossia.org/img/syndicated.gif){kind=small} syn_bx_neuro)@ 2025-05-08 03:46:00 |
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Chronic nicotine treatment enhanced cognition and reduced neuroinflammation in the gp120 transgenic mouse model of neuroHIV
Rationale: Antiretroviral development has improved the longevity of people with HIV (PWH), but many experience impaired cognition potentially due to neuroinflammation. PWH smoke cigarettes at higher rates than the general population, possibly for self medication given cognitive-enhancing and anti-inflammatory properties of nicotine, the primary psychoactive ingredient cigarette smoke. We hypothesized that chronic nicotine would improve cognition in a mouse model of HIV, gp120 transgenic (Tg) mice, and reduce neuroinflammation. Methods: Male and female gp120 Tg mice (n=64) and littermate controls (n=67) were operantly trained then tested for effortful motivation in the progressive ratio breakpoint task (PRBT). Mice were counter-balanced into three groups for saline or nicotine minipump implantation (0, 14 or 40 mg/kg/day) then retested 25 days later in the PRBT, probabilistic reversal learning task (PRLT; reinforcement learning and cognitive flexibility), and Iowa Gambling Task (IGT; risk-based decision-making), with a subset tested for neuroinflammation (Iba1 levels). Results: Gp120-Tg mice exhibited worse PRLT performance, attenuated by nicotine. Furthermore, nicotine selectively optimized their response strategies in the PRLT and IGT, increasing loss sensitivity, shifting animals towards safer responses. No motivation effects were observed. Nicotine also reduced Iba1 expression, suggesting that its cognitive-enhancing effects may relate to reduced neuroinflammation. Conclusion: Gp120 Tg mice exhibited deficits in the PRLT, which are attenuated by chronic nicotine. Furthermore, nicotine improved reinforcement learning and risky decision-making supporting its therapeutic potential for cognitive deficits in PWH, possibly via reducing neuroinflammation. With potential negative consequences of long-term nicotine use, future studies should determine its mechanism of action to develop more targeted therapeutics.
Rationale: Antiretroviral development has improved the longevity of people with HIV (PWH), but many experience impaired cognition potentially due to neuroinflammation. PWH smoke cigarettes at higher rates than the general population, possibly for self medication given cognitive-enhancing and anti-inflammatory properties of nicotine, the primary psychoactive ingredient cigarette smoke. We hypothesized that chronic nicotine would improve cognition in a mouse model of HIV, gp120 transgenic (Tg) mice, and reduce neuroinflammation. Methods: Male and female gp120 Tg mice (n=64) and littermate controls (n=67) were operantly trained then tested for effortful motivation in the progressive ratio breakpoint task (PRBT). Mice were counter-balanced into three groups for saline or nicotine minipump implantation (0, 14 or 40 mg/kg/day) then retested 25 days later in the PRBT, probabilistic reversal learning task (PRLT; reinforcement learning and cognitive flexibility), and Iowa Gambling Task (IGT; risk-based decision-making), with a subset tested for neuroinflammation (Iba1 levels). Results: Gp120-Tg mice exhibited worse PRLT performance, attenuated by nicotine. Furthermore, nicotine selectively optimized their response strategies in the PRLT and IGT, increasing loss sensitivity, shifting animals towards safer responses. No motivation effects were observed. Nicotine also reduced Iba1 expression, suggesting that its cognitive-enhancing effects may relate to reduced neuroinflammation. Conclusion: Gp120 Tg mice exhibited deficits in the PRLT, which are attenuated by chronic nicotine. Furthermore, nicotine improved reinforcement learning and risky decision-making supporting its therapeutic potential for cognitive deficits in PWH, possibly via reducing neuroinflammation. With potential negative consequences of long-term nicotine use, future studies should determine its mechanism of action to develop more targeted therapeutics.
