Major areas controlling sexual motivation and performance in males include the mesolimbic dopamine (DA) system, the medial preoptic area (MPOA), the amygdala, and the bed nucleus of the stria terminalis (BST). Genital reflexes are controlled by the MPOA, paraventricular nucleus (PVN), brainstem, and spinal cord areas. Mating is integrated by the MPOA, amygdala, BST, PVN, and mesolimbic and nigrostriatal tracts, which are also important for other social behaviors. Perinatal and adult hormones predispose the network to produce specific behaviors. Steroid hormones have primarily slow, genomically mediated effects, although they may also have rapid effects mediated by membrane receptors.