Ghrelin system of the brain participates in control of emotional, explorative behavior and motor activity in rats rearing in conditions of social isolation stress

Abstract

Wistar rats were rearing in conditions of social isolation from others beginning with 20th day of life till adulthood (90-100 days). In adult rats, a conditioned place preference (CPP) of ethanol (0.5 g/kg ip) was trained, and behavior in open field, elevated plus maze and intruder-resident test was examined. Intranasal administration of [D-Lys3]-GHRP-6, a peptide ghrelin antagonist (10 µg in 20 µl), to isolated rats blocked formation and expression (recovery) of CPP of ethanol that supported participation of ghrelin system in regulation of positive reinforcement activated by ethanol. Intranasal administration of ghrelin (20 µg in 20 µl) to rats reared in conditions of social isolation produced a typical anxiogenic effect, elevated exploratory activity, aggression signs and reduction of communicative behavior. In rats reared in conditions of social isolation, [D-Lys3]-GHRP-6, a ghrelin antagonist, possessed anxiolytic effect, reduced explorative activity, communicative behavior and aggression. It is concluded that ghrelin system of the brain participates in control of emotional, explorative behavior and motor activity in rats rearing in conditions of social isolation stress. (For citation: Shabanov PD, Vinogradov PM, Lebedev AA, et al. Ghrelin system of the brain participates in control of emotional, explorative behavior and motor activity in rats rearing in conditions of social isolation stress. Reviews on Clinical Pharmacology and Drug Therapy. 2017;15(4):38-45. doi: 10.17816/RCF15438-45).