Testosterone effects on paternal behavior and vasopressin immunoreactive projections in prairie voles (Microtus ochrogaster).

Castration reduced paternal responsiveness of male prairie voles (Microtus ochrogaster). Castration also reduced the number of vasopressin immunoreactive (AVP-ir) cells in the bed nucleus of the stria terminalis (BST) and medial amygdaloid nucleus (MA), as well as the density of AVP-ir fibers in the lateral septum. Testosterone treatment of castrated voles prevented these changes. The similarities in the effects of the hormonal manipulations on paternal responsiveness and AVP immunoreactivity provide further support for the hypothesis that AVP-ir projections of the BST and MA are implicated in paternal behavior.