Neonatal 5-hydroxytryptamine depletion induces depressive-like behavior in adult rats.

The influence of neonatal serotonergic lesion on adult behavior in locomotor and depression models was studied in male Wistar rats. When 3-day-old rats were injected intracisternally with 5,7-dihydroxytryptamine (5,7-DHT), a marked depletion of brain 5-HT was observed when animals were killed 3 months after the treatment. Brain catecholamine content was generally not changed by neurotoxin treatment. The behavioral consequence of intracisternal 5,7-DHT administration to developing rats consisted in reduction of adult rats' activity in the forced swimming test. Both desipramine, and, to the lesser extent, fluoxetine, reversed 5,7-DHT-induced immobility of animals.