The effects of amylin on aggression in wistar rats exposed to the resident-intruder paradigm

Aim: Aggression can be seen together with substanc addiction, psychiatric diseases and other health problems and can turn into violence. Our study was conducted to investigeate the effect of amylin on aggression centers in the central nervous system and its possible therapeutic effects. Materials and Methods: In our research, two experiments were carried out on rats divided into four groups. In Experiment 1, physiological saline was applied to one group of rats, while intraperitoneal amylin (50 µg/kg) was administered to the other group. In Experiment 2, intraperitoneal amylin was administered to both groups. In Experiment 2, saline was administered to one group of rats through a cannula attached to the Area Postrema (AP), and amylin antagonist was administered to the other group. After rats in all groups were housed in cages with ovariectomized females for a week, they were exposed to the Resident Intruder Paradigm with another male rat that was younger and weaker than them for 10 minutes, and the behaviors were recorded with a camera. The effects of amylin on aggression centers in rats sacrificed at the end of the process were examined with immunohistochemical and behavioral tests. Results: In Experiment 1, it was determined that amylin significantly reduced Medial Amygdala (MeA) activation and aggression behavior. In Experiment 2, it was observed that immunoreactivity increased in the Bed Nucleus of Stria Terminalis (BNST), Ventrolateral of the Ventromedial Hypothalamus (VMHvl) and MeA nuclei of rats administered amylin antagonist to the AP. Conclusion: Our findings indicate that amylin has an antiaggressive effect and that its antiaggressive effects may occur through AP.