ABS 2022
The rapid sex steroids-vasopressin interaction modulates social recognition and aggression in male mice
Dario Aspesi, Zachary B. Brill, Grace Guillaume, Sarah Matta, Swathy Sethuraman, Elena Choleris. University of Guelph, Guelph, ON, Canada

Sex steroids in males affect social recognition (SR) and aggression by rapidly interacting with neuropeptides such as arginine-vasopressin (AVP), highly expressed in the bed nucleus of the stria terminalis (BNST) and lateral septum (LS). The underlying mechanisms of this interplay are yet to be understood. Adult male mice were infused with one of different doses of Testosterone (T), 17β-estradiol (E2) or dihydrotestosterone (DHT), in the BNST to elucidate the rapid effects of steroids on SR, assessed 40 min post-infusion by a difficult paradigm. Aggression was tested with a resident-intruder paradigm to evaluate rapid and long-lasting effects. To investigate the steroids/AVP interplay, male mice received infusions of an AVP receptor 1a (α-VR1a) antagonist in the LS immediately prior to steroids in the BNST. Results revealed that all 3 steroids facilitated SR and increased the dominance score at 35-min, but only T and E2 increased dominance score at 120-min. The facilitating effects of T or E2, but not DHT, in the BNST were prevented by infusion of α-VR1a in the LS. These results suggest a complex steroids/AVP interaction, modulating SR and aggression in male mice.