Anabolic steroids differentially modulate passive avoidance learning and food intake in male and female pubertal rats: Possible role of NPY

Abstract

Anabolic androgenic steroids (AAS) are a class of steroid hormones derived from testosterone, being abused by adolescents, and known to affect anxiety, learning, and memory. The neural system underlying these behaviors includes the amygdala (AMY), a forebrain region that is known to express neuropeptide Y (NPY). NPY is one of the most abundant peptides in the brain and it plays a role in the regulation of energy homeostasis, anxiety and cognitive processes. Therefore, we aimed to assess NPY modulation in the AMY and in cognitive behavioral processes after chronic exposure to AAS in pubertal rats. Female and male pubertal rats were exposed to 17α‐methyltestosterone for two weeks. Food intake and body weight were measured during AAS exposure. For general anxiety and emotional memory, we used the Elevated Plus Maze (EPM) and the Passive Avoidance Task (PAT), respectively. Using RIA, we found a significant decrease in NPY levels in females, while there was no modulation in males. AAS in females showed an increase in body weight at the first and second weeks of AAS exposure, and an increase in food intake in the second week. In males, these differences were observed in the first, but not in the second week. Anxiety was not altered in male or female animals. Females but not males, showed a significant impairment of passive avoidance learning. Taken together, our results suggest that AAS can differentially modulate emotional memory and energy metabolism, maybe through NPY‐related neural circuits. Supported by RCMI (G12RR030551), NCRR‐NIH (P20RR016470).