Towards a new model for cellular pathophysiology in affective disorder.

The mode of action of serotonin in depression is unclear. We tested the modulation of hippocampal long-term plasticity, a model for learning and memory, by 5-HT and found a selective impairment of long-term depression resulting in a positive modification of synaptic network properties. We hypothetize a role for long-term plasticity in emotional regulation and the pathophysiology of affective disorders.