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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)
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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)
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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)
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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)
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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)
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Mon, 07 Apr 2025 00:00:00 GMT