Affiliation:
1. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences
Abstract
Previous magnetic resonance studies of the dorsal hippocampus of male rats selected for aggressive attitude to humans revealed lower contents of γ-aminobutyric acid (GABA), N-acetylaspartate, and creatine+phosphocreatine and an elevated content of phosphorylethanolamine as compared to males selected for tame behavior. We investigated the influence of early social instability environment on the hippocampal volumes and spectrum neurometabolites in the dorsal hippocampi of adult tame, aggressive, and unselected rats. The experimental social instability included early weaning, subsequent housing in twos till the age of 3 months, a daily replacement of cagemates from days 19 to 25. Animals of the control groups were weaned at the age of 30 days and kept in fours or fives until the age of 3 months. Control aggressive males were inferior to tame in hippocampal volumes, absolute and normalized to individual brain volumes. The early social instability showed no effect on these indices. In the experimental groups, lower content of phosphorylethanolamine and higher content of alanine in the dorsal hippocampus as compared to control animals were recorded only in aggressive rats. This fact may be related to the formerly observed lower level of stress response in these animals. It follows from the results that aggressive rats are more sensitive to social instability conditions. Also, the early instability conditions and selection for aggressive behavior oppositely affect phosphorylethanolamine metabolism and the integral parameters of the metabolic profile in the dorsal hippocampus.
Publisher
The Russian Academy of Sciences