Effect of olfactory bulbectomy and chronic amitryptiline treatment in rats. 3H-imipramine binding and behavioral analysis by swimming and open field tests.

An 'animal model' of depression, based on bulbectomy, followed by chronic treatment with amitryptiline was used in rats. In the synaptosomal membranes of the cerebral cortex plus hippocampus, the number of binding sites for 3H-imipramine increased significantly when bulbectomy was associated with the antidepressant. In the bulbectomized rats the tendency was toward a decrease in binding. The treatment with 0.2% Triton X-100 of the membranes revealed a large increase in postsynaptic sites in the bulbectomized treated rats. The behavioral parameters analyzed by the swimming with a water wheel and the open field test revealed a series of differences in the various groups of rats, with respect to handling, bulbectomy and antidepressant treatment. Handling resulted in an increase in swimming time in controls, while bulbectomy reduced this parameter. In both the swimming and open fields tests, chronic bulbectomy reduces the motility of the rat. In control rats chronic amitryptiline increases locomotion and exploratory activity, a behavioral effect that is even more prominent in bulbectomized treated rats.