Lesion of the bed nucleus of the stria terminalis enhances learned despair.

The bed nucleus of the stria terminalis (BNST) was lesioned in adult male Wistar rats (n = 9) and its involvement in coping behavior during forced swim stress examined. Rats remain immobile longer in the second of two swim tests, a phenomenon known as learned despair. Results revealed that, compared to sham-operated controls (n = 8), BNST-lesioned animals displayed immobility significantly earlier and for longer durations in the second swim test. Rats with BNST lesions also showed significantly reduced escape behavior in the form of fewer numbers of jumps and dives compared to controls. Mobility deficits were not due to general motor impairment as revealed by an open field test. Results suggest that the BNST may modulate coping behavior especially during uncontrollable stress.