Empathy Study in Rodent Model of Autism Spectrum Disorders

Social affective behaviors among female rats involve the basolateral amygdala and insular cortex

The ability to detect, appraise, and respond to another's emotional state is essential to social affective behavior. This is mediated by a network of brain regions responsible for integrating external cues with internal states to orchestrate situationally appropriate behavioral responses. The basolateral amygdala (BLA) and the insular cortex are reciprocally connected regions involved in social cognition and prior work in male rats revealed their contributions to social affective behavior. We investigated the functional role of these regions in female rats in a social affective preference (SAP) test in which experimental rats approach stressed juvenile but avoid stressed adult conspecifics. In separate experiments, the BLA or the insula were inhibited by local infusion of muscimol (100ng/side in 0.5μL saline) or vehicle prior to SAP tests. In both regions, muscimol interfered with preference for the stressed juvenile and naive adult, indicating that these regions are necessary for appropriate social affective behavior. In male rats, SAP behavior requires insular oxytocin but there are noteworthy sex differences in the oxytocin receptor distribution in rats. Oxytocin (500nM) administered to the insula did not alter social behavior but oxytocin infusions to the BLA increased social interaction. In sum, female rats appear to use the same BLA and insula regions for social affective behavior but sex differences exist in contribution of oxytocin in the insula.

Social affective behaviors among female rats involve the basolateral amygdala and insular cortex

The ability to detect, appraise, and respond to another's emotional state is essential to social affective behavior. This is mediated by a network of brain regions responsible for integrating external cues with internal states to orchestrate situationally appropriate behavioral responses. The basolateral amygdala (BLA) and the insular cortex are reciprocally connected regions involved in social cognition and prior work in male rats revealed their contributions to social affective behavior. We investigated the functional role of these regions in female rats in a social affective preference (SAP) test in which experimental rats approach stressed juvenile but avoid stressed adult conspecifics. In separate experiments, the BLA or the insula were inhibited by local infusion of muscimol (100ng/side in 0.5μL saline) or vehicle prior to SAP tests. In both regions, muscimol interfered with preference for the stressed juvenile and naive adult, indicating that these regions are necessary for appropriate social affective behavior. In male rats, SAP behavior requires insular oxytocin but there are noteworthy sex differences in the oxytocin receptor distribution in rats. Oxytocin (500nM) administered to the insula did not alter social behavior but oxytocin infusions to the BLA increased social interaction. In sum, female rats appear to use the same BLA and insula regions for social affective behavior but sex differences exist in contribution of oxytocin in the insula.

The Relationship between Empathy and Attachment in Children and Adolescents: Three-Level Meta-Analyses

Empathy is one of the leading social abilities to understand or feel the emotions of other people. Attachment is thought to be a critical influential factor of empathy, as revealed by attachment theory and experimental studies, while empathy is also believed to facilitate the quality of attachment. Although many studies are conducted concerning the two subjects, the direction and magnitude of their relationship still remain unclear. In order to clarify the discrepant results in the previous study and explore the moderators in the empathy-attachment association, three-level meta-analyses were conducted in the present work. Based on 212 effect sizes from 59 samples in 50 studies with a total of 24,572 participants, random effect model analyses showed that empathy was insignificantly correlated with anxious attachment, significantly negatively correlated with avoidant attachment, and significantly positively correlated with secure attachment. The meta-analytic results indicated that children and adolescents with high secure attachment tend to show more empathy than those with low secure attachment. The meta-regression model revealed significant effects of the empathy dimension, culture, empathy measurement tools, and publication state. Additionally, implications and future directions for the empathy-attachment relationship were also discussed.

An opinion on the interpretation of social release in rats

This commentary concerns a controversial animal model in rodent social release research wherein one rat releases another rat from entrapment in a plastic tube. Release from the plastic tube has been proposed as a model to study empathically motivated behaviour. However, empathic motivations have been contested by others who have provided evidence for social reinforcement motivating release behaviour. Furthermore, helping, or other forms of pro-social behaviour could exist independent of empathy or empathetic motivation and the stimuli occasioning this helping behaviour are not known. In addition, there is a dearth in the citations of published studies whose results fail to support this model. In other words, the controversial aspect of the rodent social release model is often overlooked. This controversy is described in the current opinion piece.

No preference for prosocial helping behavior in rats with concurrent social interaction opportunities

Helping behavior tasks are proposed to assess prosocial or "empathic" behavior in rodents. This paradigm characterizes the behavior of subject animals presented with the opportunity to release a conspecific from a distressing situation. Previous studies found a preference in rats for releasing restrained or distressed conspecifics over other controls (e.g., empty restrainers or inanimate objects). An empathy account was offered to explain the observed behaviors, claiming subjects were motivated to reduce the distress of others based on a rodent homologue of empathy. An opposing account attributes all previous results to subjects seeking social contact. To dissociate these two accounts for helping behavior, we presented subject rats with three simultaneous choice alternatives: releasing a restrained conspecific, engaging a nonrestrained conspecific, or not socializing. Subjects showed an initial preference for socializing with the nonrestrained conspecific, and no preference for helping. This result contradicts the empathy account, but is consistent with the social-contact account of helping behavior.

Empathy for Pain: Insula Inactivation and Systemic Treatment With Midazolam Reverses the Hyperalgesia Induced by Cohabitation With a Pair in Chronic Pain Condition

Empathy for pain is the ability to perceive and understand the pain in the other individual. Recent studies suggested that rodents have this social ability. GABAergic system has receptors in the brain structures involved in emotional processes as well as in the insular cortex. This area has been described as an important key in modulation of pain and empathy. The present study has investigated the role of insula and its Benzodiazepine-GABAA system on social modulation of pain induced by cohabiting with a mouse submitted to sciatic nerve constriction, a neuropathic pain model. The insular cortex function was assessed by the structure inactivation (Experiments 1 and 2); the role of GABA system was evaluated by systemic treatment of midazolam (MDZ 0.5, 1, and 2 mg/kg) (Experiment 3); and the role of GABAA receptors of insula were studied by bilateral MDZ (3 and 30 nmol/0.1 μl) microinjections in the structure (Experiment 4). Male Swiss mice were housed in groups or dyads. On dyads, after 14 days of cohabitation they were divided into two groups: cagemate nerve constriction and cagemate sham (CS). After 14 days of familiarity, cagemates were evaluated on the writhing test. For group-housed, insula inactivation did not change nociception. For dyad-housed, cohabiting with a mouse in chronic pain increased the nociceptive response and the insula inactivation has reverted this response. Systemic MDZ attenuated nociception and intra-insula MDZ did not alter it. Our results suggest that cohabitation with a pair in chronic pain induces hypernociception, insula possibly modulates this response and the GABA system is also possibly involved, but not its insular mechanisms.