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BioRxiv : the Preprint Server For... Jun 2024Traumatic social experiences redefine socially motivated behaviors to enhance safety and survival. Although many brain regions have been implicated in signaling a social...
Traumatic social experiences redefine socially motivated behaviors to enhance safety and survival. Although many brain regions have been implicated in signaling a social threat, the mechanisms by which global neural networks regulate such motivated behaviors remain unclear. To address this issue, we first combined traditional and modern behavioral tracking techniques in mice to assess both approach and avoidance, as well as sub-second behavioral changes, during a social threat learning task. We were able to identify previously undescribed body and tail movements during social threat learning and recognition that demonstrate unique alterations into the behavioral structure of social motivation. We then utilized inter-regional correlation analysis of brain activity after a mouse recognizes a social threat to explore functional communication amongst brain regions implicated in social motivation. Broad brain activity changes were observed within the nucleus accumbens, the paraventricular thalamus, the ventromedial hypothalamus, and the nucleus of reuniens. Inter-regional correlation analysis revealed a reshaping of the functional connectivity across the brain when mice recognize a social threat. Altogether, these findings suggest that reshaping of functional brain connectivity may be necessary to alter the behavioral structure of social motivation when a social threat is encountered.
PubMed: 38948883
DOI: 10.1101/2024.06.17.599379 -
BioRxiv : the Preprint Server For... Jun 2024Chronic social defeat stress (CSDS), a widely used rodent model of stress, reliably leads to decreased social interaction in stress susceptible animals. Here, we...
Chronic social defeat stress (CSDS), a widely used rodent model of stress, reliably leads to decreased social interaction in stress susceptible animals. Here, we investigate a role for fear learning in this response using 129Sv/Ev mice, a strain that is more vulnerable to CSDS than the commonly used C57BL/6 strain. We first demonstrate that defeated 129Sv/Ev mice avoid a CD-1 mouse, but not a conspecific, indicating that motivation to socialize is intact in this strain. CD-1 avoidance is characterized by approach behavior that results in running in the opposite direction, activity that is consistent with a threat response. We next test whether CD-1 avoidance is subject to the same behavioral changes found in traditional models of Pavlovian fear conditioning. We find that associative learning occurs across 10 days CSDS, with defeated mice learning to associate the color of the CD-1 coat with threat. This leads to the gradual acquisition of avoidance behavior, a conditioned response that can be extinguished with 7 days of repeated social interaction testing (5 tests/day). Pairing a CD-1 with a tone leads to second-order conditioning, resulting in avoidance of an enclosure without a social target. Finally, we show that social interaction with a conspecific is a highly variable response in defeated mice that may reflect individual differences in generalization of fear to other social targets. Our data indicate that fear conditioning to a social target is a key component of CSDS, implicating the involvement of fear circuits in social avoidance.
PubMed: 38948731
DOI: 10.1101/2024.06.18.599597 -
MedRxiv : the Preprint Server For... Jun 2024Elevated anxiety and uncertainty avoidance are known to exacerbate maladaptive choice in individuals with affective disorders. However, the differential roles of state...
Elevated anxiety and uncertainty avoidance are known to exacerbate maladaptive choice in individuals with affective disorders. However, the differential roles of state vs. trait anxiety remain unclear, and underlying computational mechanisms have not been thoroughly characterized. In the present study, we investigated how a somatic (interoceptive) state anxiety induction influences learning and decision-making under uncertainty in individuals with clinically significant levels of trait anxiety. A sample of 58 healthy comparisons (HCs) and 61 individuals with affective disorders (iADs; i.e., depression and/or anxiety) completed a previously validated explore-exploit decision task, with and without an added breathing resistance manipulation designed to induce state anxiety. Computational modeling revealed a pattern in which iADs showed greater information-seeking (i.e., directed exploration; Cohen's =.39, =.039) in resting conditions, but that this was reduced by the anxiety induction. The affective disorders group also showed slower learning rates across conditions (Cohen's =.52, =.003), suggesting more persistent uncertainty. These findings highlight a complex interplay between trait anxiety and state anxiety. Specifically, while elevated trait anxiety is associated with persistent uncertainty, acute somatic anxiety can paradoxically curtail exploratory behaviors, potentially reinforcing maladaptive decision-making patterns in affective disorders.
PubMed: 38947082
DOI: 10.1101/2024.06.19.24309110 -
Journal of Experimental Zoology. Part... Jul 2024Salinity can be an environmental stressor for anurans, as their highly permeable skin makes them prone to osmotic stress when exposed to saline conditions. However,...
Salinity can be an environmental stressor for anurans, as their highly permeable skin makes them prone to osmotic stress when exposed to saline conditions. However, certain anuran species have colonized areas near saltwater habitats, suggesting an ability to acclimate to saline conditions. Here, we evaluated physiological and behavioral responses to saline conditions in adult Cuban treefrogs (Osteopilus septentrionalis), an invasive anuran found throughout Florida. To examine their response to salinity, adult frogs were maintained in two treatments simulating a freshwater (0.5 ppt) or brackish (8.0 ppt) environment for 6 weeks. To assess their physiological response to this potential stressor, all frogs were submerged in a brackish solution to quantify individual weight change every 2 weeks. We found that frogs maintained in brackish solution lost more weight at Weeks 2 and 6 when compared to Week 0, suggesting that salinity may be an environmental stressor for Cuban treefrogs. Yet, the weight change at Week 4 was similar to the pre-exposure period, which may indicate that constant exposure to salinity may alter their physiological response to saline conditions. To supplement the physiological analyses, we investigated avoidance behavior toward saline conditions by offering individuals a choice between freshwater or brackish environments. Our results showed that Cuban treefrogs chose freshwater environments more frequently and may thus avoid saline ones. This study reveals that salinity may induce plastic and avoidance responses in Cuban treefrogs, potentially allowing them to expand their range into areas typically stressful for most anurans.
PubMed: 38946593
DOI: 10.1002/jez.2841 -
Psychoneuroendocrinology Jun 2024Recent research has increasingly acknowledged the impact of oral contraceptives on affective behavior and stress responses; however, the underlying mechanisms are still...
Recent research has increasingly acknowledged the impact of oral contraceptives on affective behavior and stress responses; however, the underlying mechanisms are still not well understood. Studies have previously shown that steroid hormones modulate automatic approach and avoidance behavior. Here, we thus investigated the effects of oral contraceptives on approach and avoidance behavior and whether these effects are modulated by stress. The study comprised 130 female participants, half of whom were using oral contraceptives, while the other half were not using any hormonal contraception (NC). The participants completed the Approach Avoidance Task (AAT), which measures automatic approach and avoidance behavior to socio-affective signals. The AAT was run once before and once after a stress manipulation using the Socially Evaluated Cold Pressor Test. OC users showed absent avoidance behavior to social threat signals and a stress-induced increase in approach behavior to positive social signals. The latter was found in particular in women taking androgenic acting OC, demonstrating that different OC preparations need to be taken into account in research on OC effects. However, OC and NC group did not differ in their cortisol stress response. Overall, the results suggest that OC usage impacts on approach and avoidance behavior to social signals, which might also contribute to the development of affective side effects.
PubMed: 38943719
DOI: 10.1016/j.psyneuen.2024.107111 -
Journal of Neurotrauma Jun 2024Mild traumatic brain injury (mTBI) is a significant health burden due to mTBI-related chronic debilitating cognitive and psychiatric morbidities. Recent evidence from...
Mild traumatic brain injury (mTBI) is a significant health burden due to mTBI-related chronic debilitating cognitive and psychiatric morbidities. Recent evidence from our laboratory suggests a possible dysregulation within reward/motivational circuit function at the level of a subcortical structure, the lateral habenula (LHb), where we demonstrated a causal role for hyperactive LHb in mTBI-induced motivational deficits in self-care grooming behavior in young adult male mice when exposed to mTBI injury during late adolescence (at ~8 weeks old). Here we extended this observation by further characterizing neurobehavioral effects of this repetitive closed head injury model of mTBI in both young adult male and female mice on LHb excitability, corticotropin releasing factor (CRF) modulation of LHb activity, and behavioral responses of motivation to self-care behavior, and approach versus avoidance behavior in the presence of a social- or threat-related stimulus. We show that mTBI increases LHb spontaneous tonic activity in female mice similar to what we previously observed in male mice as well as promoting LHb neuronal hyperexcitability and hyperpolarization-induced LHb bursting in both male and female mice. Interestingly, mTBI only increases LHb intrinsic excitability in male mice coincident with higher levels of the hyperpolarization-activated cation currents (HCN/Ih) and reduces levels of the M-type potassium currents while potentiating M-currents without altering intrinsic excitability in LHb neurons of female mice. Since persistent dysregulation of brain CRF systems is suggested to contribute to chronic psychiatric morbidities and that LHb neurons are highly responsive to CRF, we then tested whether LHb CRF subsystem becomes engaged following mTBI. We found that in vitro inhibition of CRF receptor type 1 (CRFR1) within the LHb reverses mTBI-induced enhancement of LHb tonic activity and hyperexcitability in both sexes, suggesting that an augmented intra-LHb CRF-CRFR1-mediated signaling contributes to the overall LHb hyperactivity following mTBI. Behaviorally, mTBI diminishes motivation for self-care grooming in female mice as in male mice. mTBI also alters defensive behaviors in the looming shadow task by shifting the innate defensive behaviors towards more passive action-locking rather than escape behaviors in response to an aerial threat in both male and female mice as well as prolonging the latency to escape responses in female mice. While, this model of mTBI reduces social preference in male mice, it induces higher social novelty seeking during the novel social encounters in both male and female mice. Overall, our study provides further translational validity for the use of this preclinical model of mTBI for investigation of mTBI-related reward circuit dysfunction and mood/motivation-related behavioral deficits in both sexes while uncovering a few sexually dimorphic neurobehavioral effects of this model that may differentially affect young males and females when exposed to this type of mTBI injury during late adolescence.
PubMed: 38943284
DOI: 10.1089/neu.2024.0184 -
Journal of Neurovirology Jun 2024The Rabies virus is a neurotropic virus that manipulates the natural cell death processes of its host to ensure its own survival and replication. Studies have shown that...
The Rabies virus is a neurotropic virus that manipulates the natural cell death processes of its host to ensure its own survival and replication. Studies have shown that the anti-apoptotic effect of the virus is mediated by one of its protein named, rabies glycoprotein (RVG). Alzheimer's disease (AD) is characterized by the loss of neural cells and memory impairment. We aim to examine whether expression of RVG in the hippocampal cells can shield the detrimental effects induced by Aβ. Oligomeric form of Aβ (oAβ) or vehicle was bilaterally microinjected into the dorsal hippocampus of male Wistar rats. One week later, two μl (10 T.U. /ml) of the lentiviral vector carrying RVG gene was injected into their dorsal hippocampus (post-treatment). In another experiment, the lentiviral vector was microinjected one week before Aβ injection (pre-treatment). One week later, the rat's brain was sliced into cross-sections, and the presence of RVG-expressing neuronal cells was confirmed using fluorescent microscopy. Rats were subjected to assessments of spatial learning and memory as well as passive avoidance using the Morris water maze (MWM) and the Shuttle box apparatuses, respectively. Protein expression of AMPA receptor subunit (GluA1) was determined using western blotting technique. In MWM, Aβ treated rats showed decelerated acquisition of the task and impairment of reference memory. RVG expression in the hippocampus prevented and restored the deficits in both pre- and post- treatment conditions, respectively. It also improved inhibitory memory in the oAβ treated rats. RVG increased the expression level of GluA1 level in the hippocampus. Based on our findings, the expression of RVG in the hippocampus has the potential to enhance both inhibitory and spatial learning abilities, ultimately improving memory performance in an AD rat model. This beneficial effect is likely attributed, at least in part, to the increased expression of GluA1-containing AMPA receptors.
PubMed: 38943023
DOI: 10.1007/s13365-024-01221-y -
Aggressive Behavior Jun 2024Aggressive behaviors have been related to approach/avoidance tendencies. In our current study, we investigated whether approach/avoidance tendencies for angry versus...
Aggressive behaviors have been related to approach/avoidance tendencies. In our current study, we investigated whether approach/avoidance tendencies for angry versus fearful emotional expressions were differentially predictive of children's reactive and proactive aggression. A total of 116 children (58 girls, M = 10.90, standard deviation SD = 0.98) completed an approach/avoidance task (AAT) and a stimulus-response compatibility task (SRCT), both measuring the extent to which they tended to approach or avoid angry and fearful facial expressions relative to neutral facial expressions. Children also completed a self-report scale of reactive and proactive aggression. Although none of the approach/avoidance tendency scores correlated significantly with either of the aggression scores, stronger approach tendencies for angry faces and stronger avoidance tendencies for fearful faces in the AAT predicted more reactive aggression. Similar yet nonsignificant results were found for proactive aggression, but no effects were replicated in the SRCT. Our results thus invite the conclusion that reactive aggression is characterized by a tendency to approach angry faces and a tendency to avoid fearful faces. However, the poor discrimination between both types of aggression as well as the lack of convergence between the results of our two measures of approach/avoidance tendencies indicates that further research is needed to establish the role of approach/avoidance tendencies for emotional faces as markers for childhood aggression.
Topics: Humans; Aggression; Female; Male; Child; Facial Expression; Anger; Fear; Avoidance Learning; Child Behavior
PubMed: 38940213
DOI: 10.1002/ab.22162 -
Archives of Sexual Behavior Jun 2024Using a vignette methodology, this study examined reactions to same-gender versus other-gender flirtation in a sample of 445 German young adults: 320 participants with a...
Using a vignette methodology, this study examined reactions to same-gender versus other-gender flirtation in a sample of 445 German young adults: 320 participants with a heterosexual orientation and 125 participants with a lesbian or gay (LG) orientation. Even in LG-friendly societies as Germany, receiving advances from someone of the same gender might still evoke heterosexuals' homonegativity. Another factor that might influence heterosexuals' reactions to same-gender flirtation is the fear of being misidentified as LG (social contagion concerns). Contrary to hypothesis, results provided little evidence to classify heterosexual participants' reactions to same-gender flirters as homonegative. Firstly, heterosexual participants showed the same degree of negative affect and avoidance behavior in the same-gender flirtation condition as LG participants did in the other-gender flirtation condition. Only positive affect scores were somewhat lower for heterosexual participants in the same-gender flirtation condition compared to LG participants in the other-gender flirtation condition. Secondly, when anti-LG attitudes and social contagion concerns were considered together, only social contagion concerns contributed to explaining variance in heterosexual participants' response to same-gender flirters. Specifically, the impact of social contagion concerns on heterosexual participants' avoidance of same-gender flirters was mediated by (lacking) positive affect, but not negative affect.
PubMed: 38937395
DOI: 10.1007/s10508-024-02935-0 -
Journal of Psychosomatic Research Jun 2024To compare the prevalence of multiple physical symptoms, coping scores, and associations between multiple physical symptoms and coping in two population-based surveys...
OBJECTIVE
To compare the prevalence of multiple physical symptoms, coping scores, and associations between multiple physical symptoms and coping in two population-based surveys within a 10-year interval.
METHODS
A nationwide study on symptoms and healthcare-seeking, the Danish Symptom Cohort, was carried out in 2012 and repeated in 2022. For each survey, 100,000 randomly selected individuals were invited, and individuals aged 20-64 years were eligible for inclusion. Multiple physical symptoms were identified using the 25-item Bodily Distress Syndrome checklist, and coping was assessed with the Brief Approach/Avoidance Coping Questionnaire. Statistical analyses included multinomial and logistic regressions.
RESULTS
A total of 35,877 were included in 2012 and 18,330 in 2022. Overall, 35.1% reported multiple physical symptoms in 2022 compared with 23.8% in 2012. The mean sum score for approach was lower in 2022 than in 2012 with a statistically significant mean difference of -1.27 (Cohen's d = -0.34), while diversion and resignation scores were significantly higher in 2022 with mean differences of 0.34 (Cohen's d = 0.11) and 0.52 (Cohen's d = 0.17), respectively. Regression analyses showed that lower approach scores and higher diversion and resignation scores were associated with an increased probability of having multiple physical symptoms in 2022, thereby confirming the results from 2012.
CONCLUSION
Over the decade, symptom reporting may have increased while coping strategies may have changed towards a slightly higher use of avoidance and lower use of approach. It seems relevant to identify modifiable contributing factors in society to prevent an acceleration of symptom reporting and avoidant behavior.
PubMed: 38936009
DOI: 10.1016/j.jpsychores.2024.111832