Lateralization of a sexually dimorphic brain area associated with steroid-sensitive behavior in the male gerbil

Emission rates of an androgen-sensitive male courtship vocalization were positively correlated with the volume of only the left hypothalamic sexually dimorphic area, pars compacta (SDApc) nucleus in sexually active male Mongolian gerbils. The asymmetric relationship between brain nucleus and vocal behavior was confirmed in testosterone (T)-treated castrated adult males but was eliminated by castration of males and did not exist in T-treated ovariectomized adult females. Interdependence between the left SDApc volume and emission rate was specific because no significant correlations were found between (a) nonvocal precopulatory or copulatory behaviors and left or right SDApc volumes and (b) a second sexually dimorphic brain area, the suprachiasmatic nucleus and vocal or other behavioral components. The asymmetric brain-behavior relationship depends on T effects in adult males and may be lateralized by perinatal T exposure.