Neurochemical effects of the reduction of social enrichment on subcortical circuitry in a novel rat model

Authors: Krishna Sangamesh Rapelli, Deborah Kreiss, Gabriel Bagatell

SUNY Campus: Binghamton University

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 51

Timeslot: Session A 9:00-10:00 AM

Abstract: Psychiatric conditions were exacerbated in severity and occurrence during the social isolation caused by COVID-19 lockdowns. These conditions arise from abnormalities in subcortical circuitry such as the basal ganglia (involved in behavioral routine and sequencing) and limbic system (involved in motivation and emotion). This study evaluated the neurochemical effects of a novel rat model of reduction in high social enrichment on targeted structures of the two systems. The present study was conducted in two cohorts over 2022 and 2023. Each cohort consisted of male (n=28) and female (n=28) rats exposed to five weeks of high social enrichment, which included daily handling sessions and ‘playdates’ with 13 other rats. For the four weeks following, experimental rats were deprived of these social interactions, while the control rats continued to experience high social enrichment. Post-mortem tissue samples of the dorsal striatum, ventral striatum, hypothalamus, and amygdala were analyzed for levels of the monoamine neurotransmitters (norepinephrine, dopamine, and serotonin) and metabolites (DOPAC, 5-HIAA) using High Performance Liquid Chromatography. Reduction of enrichment altered neurochemical levels of both sexes in the dorsal and ventral striatum, whereas only male neurochemistry was altered in the hypothalamus and amygdala. These sex differences model variations in response to environmental stressors in humans. A better understanding of the neurophysiological consequences of social isolation can lead to potential avenues for the development of new therapeutic strategies.