The hormones of the posterior pituitary are known to function in regulating water/mineral balance, stimulating contractions of the reproductive tract, and controlling lactation. Recently these hormones have been discovered to be distributed throughout the brain and have been implicated in the regulation of behaviors such as attention, learning, communication, aggression, reproduction and parenting. This project examines whether the pituitary hormone vasotocin plays a crucial role in coordinating the body's physiological responses to changing environmental conditions while at the same time modulating the individual's social behavior. The hypothesis is that environmental stress causes massive vasotocin release into the bloodstream, inhibiting gonadal function, inhibiting vasotocin action in brain areas regulating social behavior, and inhibiting reproductive behavior. In contrast, nonstressful environmental conditions decrease vasotocin release into the bloodstream while increasing its production in brain circuits modulating social behavior, leading to the onset of reproduction and paternal behavior. Experiments will measure the distribution of vasotocin in the brain and observe social behavior under different environmental conditions to test the hypothesis. If this hypothesis is correct, it suggests that it may be very difficult for the body to respond to physiological stress without inadvertently affecting social behavior.
