Behavioral neuroscience最新文献

The neuropeptide oxytocin is traditionally known for its roles in parturition, lactation, and social behavior. Other data, however, show that oxytocin can modulate behaviors outside of these contexts, including drug self-administration and some aspects of cost-benefit decision making. Here we used a pharmacological approach to investigate the contributions of oxytocin signaling to decision making under risk of explicit punishment. Female and male Long-Evans rats were trained on a risky decision-making task in which they chose between a small, "safe" food reward and a large, "risky" food reward that was accompanied by varying probabilities of mild footshock. Once stable choice behavior emerged, rats were tested in the task following acute intraperitoneal injections of oxytocin or the oxytocin receptor antagonist L-368,899. Oxytocin dose-dependently reduced preference for the large, risky reward only in females, whereas L-368,899 dose-dependently reduced preference for the large, risky reward in both sexes. Control experiments showed that these effects could not be accounted for by drug-induced alterations in preference for the large reward or shock sensitivity. Together, these results reveal partially sex-dependent effects of oxytocin signaling on risky decision making in rats. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The social and nonsocial cognitive deficits found in schizophrenia (SZ) and in individuals at risk for the illness are relatively treatment-resistant and yet are the best predictors of real-world functioning. As such, pathophysiological markers that have been shown to be remediable, and associated with cognitive and functional targets, may serve as an indirect approach to improved outcomes. Heart rate variability (HRV), a measure of autonomic adaptability, is suppressed in individuals with SZ and predictive of psychosocial function. Here, we aimed to clarify the relationships between autonomic adaptability, social cognition, and psychosocial dysfunction in individuals who may be at risk for psychosis. HRV was measured before and after a stressor task to assess baseline and recovery, and social cognition was assessed with affective valence recognition in 25 at-risk individuals who report distress to psychotic-like experiences (PLE) and 30 healthy comparisons. PLE demonstrated blunted baseline HRV, worse performance for neutral, but not positive or negative, affective faces, as well as role and social dysfunction. In PLE, significant relationships were found between negative valence accuracy and baseline HRV and role function, as well as between recovery HRV and social and role function. Group classification revealed 70.9% accuracy when using recovery HRV and role function. Results are the first to demonstrate that aberrant autonomic arousal is predictive of maladaptive social cognitive and functional behaviors in individuals who may be at risk for psychosis. Early identification of those at risk may mitigate functional decline. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

We have previously demonstrated that gonadally intact female rats become habitual following around 120 response-outcome (R-Os) exposures during operant training. This rapid development of habit does not occur in gonadally intact male rats, which remain goal-directed up to at least 320 R-Os. The present study sought to examine the effect of removing gonadal hormones on the acquisition and expression of goal-directed and habitual behaviors separately in both male and female rats. To accomplish this, separate experimental groups of adult Long-Evans rats were utilized, including intact and ovariectomized (OVX) females, as well as intact and castrated (CAST) males. All groups were trained to 240 R-Os, and one half of each experimental group was subjected to a reinforcer devaluation procedure, while the remaining half served as nondevalued controls. An extinction test was then used to determine habitual versus goal-directed behavior. Results found intact females trained to 240 R-Os showed habit and intact males trained to 240 R-Os showed goal-directed behavior. Results also found that ovariectomy disrupts habit in female rats, keeping them goal-directed at 240 R-Os, while castration in male rats produced habitual responding at 240 R-Os, thus effectively reversing the sex differences observed in intact rats at 240 R-Os. An additional experiment was done in OVX and CAST males trained to 160 R-Os to determine if gonadectomy altered goal/habit behavior earlier in instrumental learning. Results showed that both OVX females and CAST males were goal-directed at 160 R-Os. Overall, these results indicate the lack of ovarian hormones effectively delays habit in female rats, and lack of testicular hormones produces earlier habit in males. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

In humans, olfactory perception appears to be a complex and multidimensional process. Classically, intensity, hedonicity, and familiarity are the main features assessed in perceptual evaluations. Several factors are well known to modulate odor perception such as environmental context, stimulus properties, or individual characteristics. Regarding the latter, female sex hormones may play an important role in modulating odor perception. In this context, few studies have investigated whether odor perception might change during the menstrual cycle in relation to odor category and perceptual features. The aim of the present study was to compare the follicular and luteal phases in women on and off oral contraceptives for the three main characteristics of odor perception (intensity, hedonicity, and familiarity) and for different odor categories (fruit, vegetable, and environmental odors). Results showed that all odors were perceived as more intense during the luteal phase compared to the follicular phase. Hedonic ratings showed differences in responses to odor categories: Fruit odors were perceived as more pleasant during the luteal phase, while vegetable odors were perceived as more unpleasant. Familiarity ratings increased during the luteal phase for two of the three odor categories (i.e., fruit and environmental odors). Comparisons between women using hormonal contraceptives (in both phases of the cycle) and those not using hormonal contraceptives revealed no significant differences in any of the dimensions assessed or in any of the odor categories. These findings are discussed in relation to the putative role of sex hormones in olfactory perception. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

High-sucrose diet (HSD) has been related to cognitive impairments and caloric imbalance. A common link among them all is the dopamine (DA) system. However, the impact of HSD on vesicular monoamine transporter 2 and dopamine D₂ receptor is controversial. This work aimed to investigate whether sucrose and caloric intake impact vesicular monoamine transporter 2 and D₂ receptor density in rats under HSD at 20 or 40 weeks of treatment. Vesicular monoamine transporter 2 density increases in the HSD-20 weeks group without altering sucrose and caloric consumption, while D₂ receptor density remains unchanged. These results support underlying changes in the DA system, particularly in the striatum body, induced by HSD. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

The posterior parietal cortex (PPC) is an associative neocortical region that integrates multiple streams of information and is implicated in spatial cognition and decision making. In some cases, however, the PPC is not required for these functions. One possibility is that the PPC is recruited when spatial complexity is high. Yet, few studies of PPC function have explicitly manipulated environmental complexity, complexity of spatial changes, or the temporal structure of spatial tasks. To examine whether task complexity recruits PPC function, we tested rats with neurotoxic damage to the dorsal PPC on a series of tasks varying in spatial and temporal complexity. Recognition memory was first assessed in standard exploration tasks, including object recognition, object location, and object in place, as well as a more complex object task in which spatial changes occurred across multiple delays. Spatial navigation was assessed in the circular hole board maze (Barnes maze), and temporal processing was assessed in a temporal order task. PPC damage spared performance on standard recognition memory tasks but caused deficits on tasks involving changes in object configuration or multiple changes across time. PPC damage spared acquisition on the Barnes maze but impaired retention and decreased efficiency of search strategies. PPC damage did not impact temporal order memory. Overall, these results suggest that the PPC is necessary when spatial complexity of the task increases attentional and long-term memory demands. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Anxiety is highly common, and stress is a major trigger for anxiety. Anxiety includes heightened threat assessment and avoidance, but we do not fully understand which components are sensitive to stress. Rodents show a balance of exploration and avoidance that incorporates threat assessment prior to making the relatively risky decision to explore an open area. The purpose of this study was to determine if stress impacts risk assessment and if this is tied to the effects of stress on exploration. The present study used elevated plus maze (EPM) to test the effects of repeated social defeat stress (RSDS) on risk assessment behaviors in adult male rats. We then tested the effects of diazepam, an anxiolytic that reduces the impact of stress on EPM exploration, to further clarify the relationship between risk assessment and risky behavior in the EPM. We found that RSDS decreased time in the open arm, similar to prior studies. We also found that RSDS increased the likelihood of the primary risk assessment behavior, stretch and attend posture (SAP), increased SAP prior to entering an open arm, and decreased the likelihood that a rat would enter an open arm after SAP. Diazepam ameliorated the effects of RSDS on both SAP and exploratory behavior, further linking risk assessment and subsequent exploratory behaviors. These results suggest that increased risk assessment and reduced risky choices after risk assessment are tied to effects of stress on exploration and provide novel insight into how stress may increase avoidance by effects on risk assessment. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Lack of Food and Drug Administration-approved treatments for cocaine use disorder contributes to high rates of treatment attrition, relapse, and overdose. Metformin is a Type 2 diabetes drug being investigated for multiple new therapeutic indications. This study set out to determine whether metformin would impact the conditioned rewarding effects of cocaine in an abbreviated or standard two-chamber conditioned place preference (CPP) assay. Adult male (n = 73) and female (n = 82) Sprague Dawley rats were conditioned in a 7-day (abbreviated: 2 × 30 min sessions daily) or a 12-day timeline (standard: 1 × 30 min sessions daily) alternating control and treatment sessions using an unbiased design. Metformin (175 mg/kg) or saline pretreatment occurred 30 min before conditioning with cocaine (20 mg/kg) or vehicle (saline). Data showed sex differences in physiological responses to cocaine and metformin, as well as variant behavioral patterns with different conditioning paradigms. Metformin pretreatment impaired acquisition of cocaine CPP in abbreviated, but not standard conditioning among male rats only. Cocaine-induced locomotor effects are moderated with metformin pretreatment in both female and male rats in different phases of conditioning, suggesting the potential therapeutic value of symptom alleviation when tapering patients off cocaine use with the goal of abstinence. Sex differences observed highlight the importance in better understanding the unique pharmacological profiles of female and male patients. This study provides evidence supporting the potential repurposing of metformin for disrupting rewarding and psychomotor effects of cocaine, paving the way for safe, low-cost, and accessible treatment. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Video exposure is known to affect brain function, yet its impact on neurodevelopmental processes remains unclear. This study aimed to investigate whether exposure to a video depicting social behavior induces behavioral and neurological changes in socially isolated mice. On Postnatal Day (PND) 21, male mice were separated from their dams and randomly assigned to three groups: socially grouped mice; socially isolated mice (ISO), where mice were housed without any social stimulation; and social video-exposed mice (SVE), where mice were exposed to a social video played on a tablet from PND21 to PND56 under socially isolated conditions. On PND56, all animals underwent behavioral tests. Compared to the socially grouped mice and ISO group, the SVE group showed an attenuated response to amphetamine treatment. In the social cognition test, the ISO group exhibited decreased affiliative behavior and increased offensive and defensive behavior. However, the SVE group showed a partial improvement in social cognition, including increased affiliative behaviors and decreased defensive behaviors, although no changes in offensive behaviors were observed. Furthermore, the SVE group exhibited elevated levels of tyrosine hydroxylase and dopamine transporter in key social cognition regions-namely the prefrontal cortex, retrosplenial cortex, and hippocampus. This neurochemical shift implies that socially isolated mice can acquire social behaviors through exposure to video-based social interactions. These effects may be related to the compensatory response of the dopamine system, which is implicated in various psychiatric disorders. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Sexual behavior in female rats varies depending on sexual history and the combination of ovarian hormones administered to induce receptivity. Experiment 1 tested whether paced mating behavior differed in sexually experienced rats when receptivity was induced with sequential estradiol benzoate (EB) and progesterone (P) or EB-Alone. Rats gained paced mating experience under EB/P (10 μg EB 48 hr + 1 mg P 4-6 hr before mating) and then were primed with EB-Alone (2 μg EB for 6 days). Rats primed with EB-Alone were fully receptive but returned to the male more slowly, spent less time with the male, had longer interintromission intervals, showed fewer proceptive behaviors and more rejection behaviors, and had significantly longer test durations compared to when rats were primed with EB/P. Experiment 2 tested whether sexual experience-induced changes to paced mating behavior occur under both EB/P and EB-Alone hormone priming regimens. Rats received EB/P or EB-Alone prior to four paced mating tests. With sexual experience under either hormone regimen, rats showed shorter contact-return latencies to intromission, shorter interintromission intervals, and more proceptive behaviors. However, relative to EB/P-primed rats, EB-Alone-primed rats exited the male compartment more frequently after mounts and intromissions, spent less time with the male, had longer interintromission intervals, displayed fewer proceptive behaviors and more rejection behaviors, and had longer test durations, indicating lower sexual motivation. Collectively, these data illustrate that experience-enhanced paced mating behavior occurs with either EB/P or EB-Alone priming, but progesterone further facilitates mating behavior. (PsycInfo Database Record (c) 2025 APA, all rights reserved).