Serotonin Type 2a Receptor in the Prefrontal Cortex Controls Perirhinal Cortex Excitability During Object Recognition Memory Recall

Effects of aminooxyacetic acid on learning and memory function and neurochemical changes in chronic alcoholism

OBJECTIVE

This study aimed to investigate the effect of aminooxyacetic acid (AOAA) on cognitive function, particularly learning and memory, in a rat model of chronic alcoholism. Additionally, the study explored changes in cystathionine β-synthase (CBS), hydrogen sulfide (H₂S), and serotonin (5-HT) levels in the prefrontal cortex to understand the potential neurochemical mechanisms involved.

METHODS

Sixty-four male SD rats were randomly divided into four groups, with 16 rats in each: Con, Con + AOAA, Model, and Model + AOAA. The Model group received a 6 % ethanol solution for 28 days. From day 14, the Model + AOAA group was treated with daily intraperitoneal injections of AOAA (5 mg/kg) for 14 consecutive days. Cognitive function was assessed using the Morris water maze, mitochondrial function was evaluated through ATPase activity, and H₂S levels were measured. CBS and 5-HT levels in the prefrontal cortex were analyzed by immunohistochemistry.

RESULTS

Compared to the control groups, rats in the Model group exhibited significant impairments in learning and memory, increased CBS expression, elevated H₂S levels, and decreased 5-HT release. AOAA treatment improved memory performance, reduced CBS expression and H₂S levels, and increased 5-HT release, although these measures did not fully return to baseline. No significant differences were observed between the two control groups.

CONCLUSION

AOAA may alleviate cognitive deficits associated with chronic alcoholism by inhibiting CBS expression, reducing H₂S levels, and enhancing 5-HT release in the prefrontal cortex. These findings suggest AOAA as a potential therapeutic strategy for alcohol-induced cognitive impairments.

Ventral hippocampus neurons encode meal-related memory

The ability to encode and retrieve meal-related information is critical to efficiently guide energy acquisition and consumption, yet the underlying neural processes remain elusive. Here we reveal that ventral hippocampus (HPCv) neuronal activity dynamically elevates during meal consumption and this response is highly predictive of subsequent performance in a foraging-related spatial memory task. Targeted recombination-mediated ablation of HPCv meal-responsive neurons impairs foraging-related spatial memory without influencing food motivation, anxiety-like behavior, or escape-mediated spatial memory. These HPCv meal-responsive neurons project to the lateral hypothalamic area (LHA) and single-nucleus RNA sequencing and in situ hybridization analyses indicate they are enriched in serotonin 2a receptors (5HT2aR). Either chemogenetic silencing of HPCv-to-LHA projections or intra-HPCv 5HT2aR antagonist yielded foraging-related spatial memory deficits, as well as alterations in caloric intake and the temporal sequence of spontaneous meal consumption. Collective results identify a population of HPCv neurons that dynamically respond to eating to encode meal-related memories.

Psilocybin prevents reinstatement of alcohol seeking by disrupting the reconsolidation of alcohol-related memories

BACKGROUND

For most psychiatric conditions, including alcohol use disorder (AUD), FDA-approved pharmacological treatments are limited and their efficacy is restricted to only certain subgroups of patients. Scientific interest in the potential of psychedelic drugs has dramatically increased because of clinical preliminary evidence of efficacy in treating various psychiatric disorders. One of the most promising compounds belonging to this class of molecules is psilocybin. Here, to elucidate the therapeutic potential and treatment modalities of this drug, we investigated the effect of psilocybin on alcohol drinking and seeking in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats, a well validated animal model of AUD characterized by excessive drinking and seeking.

METHODS

Using male and female msP rats, we tested the effect of psilocybin on home cage voluntary alcohol consumption. We also tested the effect of the drug on the alcohol deprivation effect (ADE) model of relapse and on cue-induced reinstatement of alcohol seeking after a period of abstinence. Finally, we evaluated if psilocybin may disrupt the reconsolidation process of alcohol-related memory.

RESULTS

Psilocybin did not reduce alcohol consumption, nor it prevented increased alcohol drinking after a period of forced abstinence and cue-induced reinstatement of alcohol-seeking. Noteworthy, in a memory retrieval-reconsolidation paradigm, psilocybin markedly attenuated resumption of alcohol seeking.

CONCLUSIONS

Altogether these data suggest that, despite psilocybin does not affect alcohol drinking and relapse, it may be highly effective if used to block the reconsolidation process of alcohol-related memories. This opens to the possibility of using this psychedelic drug in clinical settings in which AUD patients undergo procedures to recall the memory of alcohol and are then treated with psilocybin during the memory reconsolidation phase.

Aerobic Exercise Alleviates the Impairment of Cognitive Control Ability Induced by Sleep Deprivation in College Students: Research Based on Go/NoGo Task

The purpose of this study was to observe whether aerobic exercise is able to alleviate the impairment of cognitive control ability in college students by sleep deprivation through cognitive control (Go-NoGo task) and blood-based markers. Taking 30 healthy college students (15 males and 15 females) as participants, using a random cross-over design within groups, respectively perform one night of sleep deprivation and one night of normal sleep (8 h). The exercise intervention modality was to complete a 30-min session of moderate-intensity aerobic exercise on a power bicycle. Change in cognitive control was assessed using the Go/NoGo task paradigm; 5-ht and blood glucose contentwere determined by enzyme-linked immuno sorbent assay and glucose oxidase electrode Measurement, respectively. The results showed that sleep deprivation could significantly reduce the response inhibition ability and response execution ability, and significantly reduce the blood 5-ht content (p< 0.01). Thirty minutes of moderate intensity aerobic exercise intervention significantly increased response inhibition ability and response execution ability, significantly increased blood 5-ht content (p<0.01), and did not change serum glucose levels. Conclusion: An acute aerobic exercise can alleviate the cognitive control impairment caused by sleep deprivation, and 5-ht may be one of the possible mechanisms by which aerobic exercise alleviates the cognitive control impairment caused by sleep deprivation.