Neuronal, Affective, and Sensory Correlates of Targeted Helping Behavior in Male and Female Sprague Dawley Rats

Abstract

Empathy is an innate ability to understand the emotional states of others along with the motivation to improve it. It has evolved over time into highly complex behaviors, the basis of which can be described using the Perception Action Model (PAM), where shared affect promotes an action that eliminates the distress of both the passive "Target" and, by extension, the active "Observer." There are myriad biological variables that may modulate empathic behavior, including sex, sensory modalities, and neural activity. In the following studies, using our labs model of social contact-independent targeted helping, we first tested whether sex differences exist in helping behavior. Next, we explored sex differences in sensory and affective signaling, including the impact of direct visualization of a distressed conspecific and the type of ultrasonic vocalizations (USV) made between animal pairs during the task. Finally, we examined the neural activity of multiple cortical and subcortical regions of interest across time during targeted helping between males and females. We show both sexes exhibit similar helping behavior, but sensory and affective signaling differs between sexes. Further, changes in neural activity exhibited distinct sex-specific patterns across time. Our results indicate sex differences are not a ubiquitous presence in targeted helping. Instead, it is likely sex differences may be a convergent phenomenon in which the behavior is similar, but the underlying biological mechanisms are distinct. These results lay the groundwork for future studies to explore the similarities and differences that drive empathic behavior in both males and females.