Effects of chronic antidepressants and electroconvulsive shock on serotonergic neurotransmission in the rat hypothalamus

The hypothalamus may play a critical role in the pathophysiology and treatment of depression, There are two main lines of evidence for this: firstly, many of its functions correspond to those altered in depression: and secondly, many hypothalamic functions are regulated by the serotonergic system, which is a common target of antidepressant treatments. In keeping with observations from other laboratories, we have found that chronic antidepressants and electroconvulsive shock increase serotonergic neurotransmission in the rat hypothalamus by inducing desensitization of presynaptic autoreceptors. we have also found that chronic hypercorticosolemia. which constitutes a model of depression, has an opposite effect, We postulate that presynaptic autoregulation of serotonergic neurotransmission in the hypothalamus may play a critical role in the pathophysiology and treatment of depression. (C) 2002 Published by Elsevier Science Inc.