Neuroendocrine basis of dominance behaviour in male rabbits

Abstract

Testosterone (T) and serotonin (5-HT) may exert different influences on socio-sexual behaviour: the former excitatory; the latter, inhibitory. The action of these two substances at the central level is strictly related, and so in this work we studied, T and estradiol (E) plasma levels and 5-HT concentration in the brain of male rabbits of different social status. Plasma T was significantly higher in dominants than in subordinates at the end but not at the beginning of the observations. Reversely plasma E was significantly lower in dominants than in subordinates at the end but not at the beginning of the observations. 5-HT was significantly lower in dominants than in subordinates in both the mesencephalon and the hippocampus. However no significant correlation was evident, at the individual level, between steroids and 5-HT.