Neonatal brain damage and recovery: intraventricular injection of NGF at time of injury alters performance of active avoidance.

Rats were given lesions of either the ventromedial hypothalamus (VMH) or septal nucleus at 7 days of age and then were tested repeatedly in an active avoidance task (A.A.) from 20 to 80 days. VMH rats were consistently impaired on the A.A. task beginning at 40 days of age. The animals with septal lesions performed the A.A. task consistently better than VMH or control animals throughout the entire test period, the septal syndrome becoming more pronounced as the rats reached maturity. In intact rats a single, intraventricular injection of NGF given at 7 days of age resulted in a greater reactivity, especially as the rats approached maturity. NGF, given at time of surgery, also improved performance of the A.A. task in VMH-damaged rats tested at 40-80 days. In rats given septal lesions, NGF treatment at time of injury attenuated the septal syndrome of improved A.A. performance. The data indicate that NGF treatment, given to neonatal rats, can produce long-lasting effects on CNS functions and can contribute to functional recovery from brain lesions.