Physiology & Behavior最新文献

{"title":"Meranzin Hydrate ameliorates “atherosclerotic depression” in ApoE−/− mice by restoring gut microbiota—driven microbial-inflammatory circuitry","authors":"Wenya Huang,&nbsp;Le Zhang,&nbsp;Chendong Xu,&nbsp;Zhifang Cai,&nbsp;Haotian Qian,&nbsp;Min Xu,&nbsp;Xi Huang","doi":"10.1016/j.physbeh.2025.115100","DOIUrl":"10.1016/j.physbeh.2025.115100","url":null,"abstract":"<div><h3>Background</h3><div>Depression and atherosclerosis frequently co-occur, with disrupted gut microbiota–driven inflammatory circuitry emerging as a shared pathogenic mechanism. To address this, we operationally define “atherosclerotic depression” as depression comorbidity with atherosclerosis. Despite its clinical significance, integrated therapeutic strategies remain lacking.</div></div><div><h3>Methods</h3><div>An ApoE^−/− mouse model combining high-fat diet feeding and acute restraint stress was established to mimic atherosclerosis-associated depression. Animals received Meranzin Hydrate (MH) treatment, followed by comprehensive assessments. Metabolic and vascular endpoints included body weight, serum lipid profiles, and aortic plaque burden (Oil Red O staining). Depressive-like behaviors were evaluated through standardized behavioral tests. BOLD-fMRI with regional homogeneity (ReHo) analysis measured brain functional activity. Gut microbiota profiling was performed by 16S rRNA sequencing to assess α-/β-diversity, Firmicutes/Bacteroidetes ratio, and keystone taxa. Inflammatory and neurotrophic markers were examined via ELISA (5-hydroxytryptamine, brain-derived neurotrophic factor, interleukin-6, endothelial nitric oxide synthase, and ghrelin), while protein and mRNA levels of vascular cell adhesion molecule-1, interleukin-1β, tumor necrosis factor-α, and ghrelin were analyzed by Western blot and RT-PCR<strong>.</strong></div></div><div><h3>Results</h3><div>MH significantly reduced aortic plaque formation, improved lipid profiles, and alleviated depressive-like behaviors. MH restored gut microbiota homeostasis by enhancing α-diversity, normalizing the Firmicutes/Bacteroidetes ratio, and enriching beneficial taxa such as Akkermansia and Allobaculum. These microbiota changes paralleled the reversal of stress- and diet-induced BOLD-fMRI alterations in emotion-regulation regions (hippocampus and prefrontal cortex). Inflammatory circuitry was rebalanced, as evidenced by reduced IL-6, TNF-α, IL-1β, and VCAM-1, alongside restored hippocampal and cardiac 5-HT, BDNF, and ghrelin levels.</div></div><div><h3>Conclusion</h3><div>MH demonstrates therapeutic potential in alleviating atherosclerosis co-depression by modulating acute mental stress-induced vascular inflammation, neurotrophic factors, brain function, and gut microbiota.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115100"},"PeriodicalIF":2.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145041099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute and repeated low dose lipopolysaccharide differentially influences opposite-sex odour preference in male and female mice","authors":"Dante Cantini ,&nbsp;Elena Choleris ,&nbsp;Martin Kavaliers","doi":"10.1016/j.physbeh.2025.115103","DOIUrl":"10.1016/j.physbeh.2025.115103","url":null,"abstract":"<div><div>Infection threat affects social preferences and mate choice across species. Female mice have been shown to avoid the odours of sick males acutely treated with relatively high doses of lipopolysaccharide (LPS), the cell wall of Gram-negative bacteria. However, less is known about the responses of both sexes to more naturalistic low level infection threat. Here we considered the responses of both male and female mice to the odours of opposite sex individuals acutely and repeatedly treated with very low and low doses of LPS (1.0 and 25 μg/kg, respectively). There was minimal avoidance of the odours of individuals acutely treated with 1.0 μg/kg LPS, whereas repeated treatment (days 1, 4 and 7), which elicited sensitization (priming), resulted in significant Day 7 avoidance. Conversely, the odours of individuals acutely treated with 25 μg/kg of LPS elicited significant avoidance, whereas repeated treatment, which lead to the development of tolerance, attenuated avoidance. In all cases females displayed a greater avoidance than males of opposite sex odours. Our results show that both male and female mice are sensitive to the nature of the infection status and threat conveyed by the olfactory cues associated with low levels of infection.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115103"},"PeriodicalIF":2.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased alcohol intake and alcohol use disorder following bariatric surgery: potential mechanisms","authors":"Allan Geliebter","doi":"10.1016/j.physbeh.2025.115094","DOIUrl":"10.1016/j.physbeh.2025.115094","url":null,"abstract":"<div><div>Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the most effective weight loss procedures for severe obesity. However, there is recent evidence of increased alcohol intake and new onset alcohol use disorder (AUD) by 2 years following both operations. Although the two surgeries differ anatomically, they lead to similar increased drinking. The mechanisms behind increased alcohol intake post-surgery remain unclear. One theory is that with a marked reduction in food intake post-surgery, there is an \"addiction\" transfer from food to alcohol intake. Another theory implicates the higher rate of absorption of alcohol post-SG and post-RYGB for the increased alcohol intake. Elucidating the mechanisms could help provide new therapeutic targets for preventing increased alcohol intake and AUD, as well as identify measures that could be used in a clinical setting to help predict the likelihood of AUD. These findings could also help guide the development of new surgical procedures that do not lead to increased alcohol intake.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115094"},"PeriodicalIF":2.5,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145030392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Children’s satiety responsiveness moderates the association between food reinforcement and eating in the absence of hunger","authors":"Kyle Hallisky ,&nbsp;Alaina L. Pearce ,&nbsp;Bari Fuchs ,&nbsp;Benjamin A. Baney ,&nbsp;Sruthi Ramesh ,&nbsp;Stephen J. Wilson ,&nbsp;Travis Masterson ,&nbsp;Emma J. Rose ,&nbsp;Amanda Bruce ,&nbsp;Seung-Lark Lim ,&nbsp;Kathleen L. Keller","doi":"10.1016/j.physbeh.2025.115092","DOIUrl":"10.1016/j.physbeh.2025.115092","url":null,"abstract":"<div><div>The reinforcing value of food, a measure of motivation to obtain food, is associated with obesity in children. However, the extent to which food reinforcement predicts children’s intake under different contexts (i.e., meals fasted, eating in the absence of hunger-EAH) is unknown. We hypothesized that food reinforcement would be positively associated with intake at meals and EAH and examined whether satiety responsiveness (SR) moderates this association. As part of an ongoing 5-visit study, 96 children (7–9 years &lt;95th BMI%) completed a Relative Reinforcing Value task (visit-V1) to assess willingness to work for candy and toys. Thirty minutes before the task, children consumed an ad libitum multi-item meal (grilled cheese, chicken tenders, etc.). On V3 and V4, children consumed the same meal followed 20 min later by presentation of nine snacks for measurement of EAH. SR was assessed from parent report (Children’s Eating Behavior Questionnaire). Mixed effect regressions showed a positive association between food reinforcement and energy intake at the meals (<em>p</em> &lt; 0.01). SR was negatively associated with food reinforcement (<em>p</em> = 0.03) and moderated the association between food reinforcement and EAH (<em>p</em> = 0.03). In children with low SR (-1SD below mean), food reinforcement and EAH were positively associated (<em>p</em> = 0.03). No associations were seen in children with SR near or above the mean. This demonstrates that willingness to work for food is associated with greater energy intake during a meal across children and EAH among children with low sensitivity to satiety cues. Interventions promoting SR may help mitigate effects of food reinforcement on non-hunger-related intake.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115092"},"PeriodicalIF":2.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145016109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response characteristics of barrel cortical neurons in layers IV/V of juvenile rats with autism-like traits after tactile stimulation","authors":"Mohammad Reza Afarinesh ,&nbsp;Bi Bi Marzieh Ahmadi ,&nbsp;Mansoureh Sabzalizadeh ,&nbsp;Vahid Sheibani","doi":"10.1016/j.physbeh.2025.115093","DOIUrl":"10.1016/j.physbeh.2025.115093","url":null,"abstract":"<div><div>The barrel cortex is a specialized region of the primary somatosensory cortex that processes tactile information from whiskers. This study investigates how tactile stimulation (TS) affects excitatory receptive fields and surrounds suppression in barrel cortex neurons of male and female autistic-like rats, using various whisker displacement protocols. The animals were categorized into control, Valproic acid pre-treated (Val), and Val-TS treatment groups. In male Val-TS rats, TS reduced layer IV ON/OFF amplitudes for principal and adjacent whisker displacements, while only OFF response latency to principal whisker displacement decreased. In females, Val group showed increased ON/OFF amplitudes, which decreased in Val-TS, returning to control levels. ON/OFF response latency to principal whisker displacement increased in Val-TS, returning to control. Tactile stimulation more effectively remodeled receptive fields and temporal timing in female barrel cortex. In layer V, male Val-TS rats showed no significant amplitude differences but decreased ON/OFF latencies to principal whisker displacement. Adjacent whisker responses were largely unchanged. In females, Val-TS rats had increased ON/OFF amplitudes to principal whisker displacement, but no latency changes. Adjacent whisker responses showed amplitude and latency differences, suggesting receptive-field expansion and remodeling. In terms of inhibitory responses, conditioning test (CT) ratio analysis indicated significant group effects for both ON and OFF responses in layer IV, with the Val-TS group showing higher CT-ratios than the Val and control groups for both sexes. Layer V responses indicated similar trends, with elevated CT-ratios in male rats under Val-TS conditions, whereas females did not show significant differences. Overall, these findings reveal distinct variations in responses of the barrel cortex neurons based on sex and treatment conditions, emphasizing the nuanced impact of interventions on neuronal responsiveness. This research enhances our understanding of sex-dependent neural adaptations and their implications for sensory processing and neuroplasticity in response to external stimuli.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115093"},"PeriodicalIF":2.5,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145016034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Placebo effect of carbohydrates on muscle force production in male collegiate athletes: The role of misinformation and feedback-reinforced cues","authors":"Man Ying Lee,&nbsp;Victor Selvarajah Selvanayagam,&nbsp;Teng Keen Khong,&nbsp;Ashril Yusof","doi":"10.1016/j.physbeh.2025.115083","DOIUrl":"10.1016/j.physbeh.2025.115083","url":null,"abstract":"<div><div>A carbohydrate placebo (CHO-PLA) is a non-metabolic substance guised as carbohydrate. When information about the treatment was not disclosed, CHO-PLA enhanced strength performance through the sweetness cue, which psychologically strengthened participants' belief in its efficacy. However, the effects of CHO-PLA when participants are misinformed that they are consuming actual carbohydrates, and the role of additional cues (visual reinforcement), remain less understood. Active males (<em>n</em> = 45) were assigned to either misinformed (MIS), misinformed with feedback reinforced (MIS+<em>R</em>) or control groups. Isokinetic force production during knee extension and flexion was measured before (pre-test) and after (post-test) CHO-PLA ingestion. A fatiguing task involving a single set of repetitions to failure for knee extension and flexion, respectively was conducted a week later to assess rate of force decline. After CHO-PLA ingestion, the MIS and MIS+<em>R</em> groups showed a 5.7 and 6.9 % increase in knee extension strength, respectively (<em>p</em> &lt; 0.05). For flexion, only the MIS+<em>R</em> group demonstrated improvement (4.9 %; <em>p</em> &lt; 0.05). Additionally, the MIS+<em>R</em> group showed the smallest decline in force (rate constant) during the fatiguing task, which corresponded to the highest total work done. These findings suggest that force production is greater when feedback reinforcement is provided (MIS+<em>R</em>). The findings also indicate that the placebo effect is strongest when all three cues, sweetness, verbal information, and visual feedback are present. In summary, the observed improvements in force production appear to be behavioral; when participants were misinformed and reinforced about the treatment received, their belief in having consumed carbohydrate was strengthened, leading to enhanced strength performance.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115083"},"PeriodicalIF":2.5,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of aerobic exercise and whole-body vibration interventions on myokines and neurocognitive performance in postmenopausal women","authors":"Chia-Liang Tsai","doi":"10.1016/j.physbeh.2025.115082","DOIUrl":"10.1016/j.physbeh.2025.115082","url":null,"abstract":"<div><div>This study investigated the effects of moderate-intensity aerobic exercise (MIAE) and MIAE combined with isometric resistance exercise on a whole-body vibration (WBV) platform (MIAE+WBV) compared with the effects of no exercise (NEI) on neurocognitive and molecular indices in 71 sedentary, healthy postmenopausal women. Participants were randomly assigned to MIAE (<em>n</em> = 23), MIAE+WBV (<em>n</em> = 23), and NEI (<em>n</em> = 25) groups. Neurocognitive measures, including accuracy rate (AR), reaction time (RT), and electroencephalogram-based event-related potentials (P2, N2, and P3 components) during the Stroop task, in addition to serum levels of insulin-like growth factor 1 (IGF-1), norepinephrine (NE), osteocalcin (OC), carboxylated OC (cOC), and uncarboxylated OC (ucOC), were evaluated before and after the intervention. Although no significant changes were observed in reaction times (RT), ERP latencies, or N2 or P3 amplitudes for the compatible condition, both exercise groups showed significant increases in accuracy rate (AR) and P3 amplitude for the incompatible condition. Only the MIAE+WBV group exhibited improvements in ARs for the compatible condition and P2 amplitudes for the incompatible condition. After exercise, both groups exhibited elevated IGF-1, NE, OC, and ucOC levels, with WBV following MIAE resulting in increases in IGF-1, OC, cOC, and ucOC in the MIAE+WBV group. Significant correlations were observed between changes in NE and P3 amplitude and between ucOC levels and ARs, highlighting links between molecular and neurocognitive outcomes. The study shows that both MIAE and MIAE+WBV can be effective approaches to improving neurocognitive and bone health in postmenopausal women, with MIAE+WBV being more effective than MIAE alone.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115082"},"PeriodicalIF":2.5,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel biting rod model for assessing aggressive behavior in restraint-stressed rats: Role of 5-HT3 receptor and NF-κB-kynurenine pathways","authors":"Akshay K. Chaudhari ,&nbsp;Kamini R. Shirasath ,&nbsp;Sameer N. Goyal,&nbsp;Kartik T. Nakhate,&nbsp;Sanjay N. Awathale","doi":"10.1016/j.physbeh.2025.115091","DOIUrl":"10.1016/j.physbeh.2025.115091","url":null,"abstract":"<div><div>Preclinical models are essential for understanding the pathophysiology of intermittent explosive disorder (IED) in rodents. However, current models fail to fully uncover the molecular mechanisms behind restraint stress-induced aggression. We introduced a restrainer combined with a biting rod to measure IED-associated symptoms in stressed rats. Activation of 5-HT3 receptors promotes aggression by increasing pro-inflammatory cytokines and nuclear factor kappa B (NF-κB) activity in the brain. NF-κB, in turn, upregulates indoleamine 2,3-dioxygenase 1 (Ido1), which converts tryptophan (a serotonin precursor) into kynurenine, depleting serotonin levels in the amygdala. We examined the roles of 5-HT3 receptors and Ido1 in driving aggression in restrained-stressed rats. Aggressive behavior of rats was assessed in a restrainer with a biting assembly after ondansetron (5-HT3 antagonist) and minocycline (kynurenine pathway inhibitor) treatments. Pro-inflammatory cytokines and NF-κB levels in the amygdala were measured using ELISA and immunohistochemistry. HPLC quantified kynurenine and tryptophan, while Golgi-Cox staining analyzed dendritic spines. Restraint stress induced extensive biting (aggression), elevated pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), and increased NF-κB expression in the amygdala. Elevated kynurenine and decreased tryptophan levels and dendritic spine density were also noticed. Blocking 5-HT3 receptors and inhibiting kynurenine pathway reduced cytokines, kynurenine, and restored tryptophan and spine density. Compared to existing methods, our model offers a more accurate assessment of restraint stress-induced aggression, incorporating molecular pathways and behavioral measures, enhancing understanding of IED. Moreover, stress-induced 5-HT3 signaling may activate NF-κB and kynurenine pathways in the amygdala, potentially contributing to the development of aggressive behavior in rodents.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115091"},"PeriodicalIF":2.5,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145006551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Social familiarity-dependent modulation of emotional responses to stressed conspecifics and the role of oxytocin receptors in rats","authors":"Rikako Mizuhara ,&nbsp;Seiichiro Amemiya ,&nbsp;Takumi Maruyama ,&nbsp;Ichiro Kita","doi":"10.1016/j.physbeh.2025.115081","DOIUrl":"10.1016/j.physbeh.2025.115081","url":null,"abstract":"<div><div>Empathy, the ability to recognize and respond to others’ emotions, enables individuals to experience emotions that either align with or differ from those of others. In rodents, emotional contagion is well established, as they reflexively express similar negative emotions when exposed to a stressed conspecific. However, because emotional responses toward others do not always result in direct contagion, whether they can modulate their emotional responses based on the social context remains unclear. Therefore, this study aimed to investigate whether rats exhibit distinct emotional responses to stressed conspecifics restrained in a container, depending on familiarity as a social factor. The elevated plus maze was employed as a method capable of capturing a broad range of emotional responses. Our findings revealed that, compared with a control condition without a conspecific, observer rats exhibited different emotional responses depending on the familiarity of the stressed conspecific. When paired with a familiar stressed conspecific, they showed increased anxiety-like behavior, spending less time in the open arms of the maze. By contrast, when paired with an unfamiliar stressed conspecific, they spent more time in the open arms displaying greater exploratory motivation. These context-dependent emotional responses were suppressed by intracerebroventricular administration of an oxytocin receptor antagonist (L-368,899 hydrochloride), targeting a neuropeptide that regulates sociality. The present findings suggest that rats not only mirror the emotions of stressed conspecifics, but also are capable of adjusting their emotional responses based on the social context, which may reflect their ability to consider both the emotions and social situations of others adaptively.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115081"},"PeriodicalIF":2.5,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145001380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"To play or not to play? Effects of social isolation length and stimulus rat familiarity on social play engagement in three laboratory rat strains","authors":"Isabella C. Orsucci ,&nbsp;Kira D. Becker ,&nbsp;Jackson R. Ham ,&nbsp;Jessica D.A. Lee ,&nbsp;Samantha M. Bowden ,&nbsp;Alexa H. Veenema","doi":"10.1016/j.physbeh.2025.115080","DOIUrl":"10.1016/j.physbeh.2025.115080","url":null,"abstract":"<div><div>Social play is displayed by juveniles of many mammalian species and is vital to the development of social skills as shown in humans and rats. Here, we determined how two external conditions, social isolation length and social stimulus familiarity, modulate social play levels (by the experimental animals) and social play defense tactics (by the stimulus animals) in juveniles of three common laboratory rat strains: Long-Evans, Sprague-Dawley, and Wistar. Experimental rats were socially isolated for either 2 h or 48 h and were then exposed in their home cage to a familiar (cage mate) or novel sex-, age-, and strain-matched stimulus rat. We found that Long-Evans rats played more with familiar than with novel rats, irrespective of time isolated, Sprague-Dawley rats played the most in the 48h-Familiar condition, and Wistar rats played the least in the 2h-Familiar condition. Moreover, Wistar rats played more with novel rats than Long-Evans and Sprague-Dawley rats. Among the defense tactics analyzed, Long-Evans and Sprague-Dawley stimulus rats showed more counter nape attacks with familiar than with novel rats, Sprague-Dawley stimulus rats also showed more counter nape attacks after a 2 h versus 48 h isolation while Wistar rats showed more counter nape attacks after a 48 h versus 2 h isolation. The effects of the external conditions on social play levels and defense tactics were similar across sex for the three strains. Overall, more social play and more counter nape attacks were observed with a familiar playmate in Long-Evans rats, with a familiar playmate and 48 h isolation (social play) or 2 h isolation (counter nape attacks) in Sprague-Dawley rats, and with a familiar or novel playmate after 48 h isolation in Wistar rats. Future research could determine whether strain differences in neuronal mechanisms underlie these condition-induced variations in social play engagement.</div></div>","PeriodicalId":20201,"journal":{"name":"Physiology & Behavior","volume":"302 ","pages":"Article 115080"},"PeriodicalIF":2.5,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145001341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}