Effect of neonatal handling on learned helplessness model of depression.

The present study was undertaken to investigate the effects of neonatal handling on learned helplessness (LH) model of depression in the rat. We also investigated the effect of neonatal handling on behavior in an open field test of emotionality. The handling procedure reduced helplessness behavior, with a decrease in the number of escape failures, an increase in the number of avoidance responses, and a decrease in the escape latency in the shuttle-box after induction of LH. In addition, handling during infancy decreased the number of boli in an open field test, which suggests that the level of emotivity in adulthood was reduced. It is suggested that handling in infancy improves behavioral adaptation to the environment, including enhanced adaptive response to stress.