Behavioral neuroscience最新文献

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).

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).

At the core of adaptive behavior is the ability to accurately predict relationships between environmental events. Such predictions require associative relationships to be updated in the face of changing contingencies. One example of such updating is the overexpectation effect. Prior investigations into overexpectation in the appetitive domain revealed that female rats require additional training to manifest the effect compared to males. This finding raises two possibilities, namely, that females are also slower at updating (reducing) fear expectancies in overexpectation, reflecting a general learning trait across valence domains, or, conversely, that they are comparable or perhaps even faster at reducing fear expectancies compared to males. To test these hypotheses, we trained male and female rats in aversive overexpectation. Our results show that while males show the overexpectation effect following two trials of overexpectation training, females are less likely to do so given the same parameters. Increasing the number of overexpectation training trials from two to four yielded a successful overexpectation effect in females. These results align with prior research in the appetitive domain (Lay, Frate, et al., 2020), providing evidence that females require more trials to downregulate previously acquired associations, whether the outcome is appetitive or aversive. These data carry important implications for the behavioral, neural, and hormonal mechanisms that support reduction in conditioned responding in both sexes and may shed light on sex differences reported in anxiety-related disorders. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Consolidated long-term memories can be modified when destabilized at reactivation (RA). This must be followed by an upregulation of protein synthesis to return the memory to a stable state. Reconsolidation is suggested to maintain the relevance of stored memories, preserving behavioral flexibility. Older or strongly encoded memories resist reconsolidation because of biological boundary conditions and destabilization of such memories is more likely in the presence of prediction error at reactivation. The neurotransmitter dopamine (DA), which has been implicated in prediction error, has been linked to destabilization using appetitive or aversive memory paradigms. However, more neutral memories also undergo modification to adapt to changing environments. Evidence suggests that a salient novel cue presented at reactivation can trigger destabilization of boundary condition-protected object memories, but DA has not yet been implicated in this process. Using male rats in a modified spontaneous object recognition task, we report that systemic administration of the D1 receptor (D1R) antagonist SCH23390 blocked recently encoded and novelty-induced relatively remote object memory destabilization. Further, systemic administration of the D1R agonist SKF38393 promoted destabilization of relatively remote memory traces in the absence of salient novelty at reactivation. Finally, systemic D1R antagonism and agonism blocked and promoted integrative memory updating, respectively, in the postreactivation object memory modification task. This work therefore advances current knowledge related to the role of DA in the dynamic nature of memory storage. (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).

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).

Individuals diagnosed with stress-related psychiatric disorders in adulthood are likely to have experienced early life stress, suggesting that early adversity is an important vulnerability factor in the subsequent development of trauma- and anxiety-related psychiatric illness. It is important to develop animal models of psychiatric dysfunction to determine evident vulnerability considerations, potential biomarkers, and novel treatment avenues to improve the human condition. In our model of acute early life stress (aELS), 15 footshocks are delivered in a single session on postnatal day 17. The following experiments investigated the persistent impacts of our aELS procedure on stress-enhanced fear learning, anxiety-related behaviors, maintenance of fear, and resistance to extinction in adult male and female rats. The findings from these experiments demonstrate that our aELS procedure yields enhanced fear learning and increased anxiety. This enhanced fear is maintained over time, yet it extinguishes normally. Taken together, these results demonstrate that exposure to 15 footshocks during a single session early in life (postnatal day 17) recapitulates a number of important features of trauma- and anxiety-related disorder symptomatology, but not others. Future studies are needed to determine the persistent physiological phenotypes resulting from aELS and the neurobiological mechanisms that mediate these long-term changes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).