Chronic imipramine treatment partially reverses the long-term changes of hippocampal synaptic plasticity in socially stressed rats

In the present study, we investigated whether synaptic plasticity changes i n the hippocampus of depressive-like socially stressed rats could be revers ed by chronic antidepressant treatment. To that end, rats were either defea ted and subsequently individually housed or subjected to control treatment followed by social housing. After a period of at least 3 months, rats were either treated chronically with imipramine (20 mg/kg per day, per os for at least 3 months) or the solvent solution (i.e. water). Then, long-term pote ntiation and depression were measured in the CA1 region of the hippocampus in vitro. Chronic imipramine treatment partially restored the attenuated in duction of long-term potentiation and suppressed the facilitation of long-t erm depression-induction in socially stressed rats. The altered synaptic pl asticity after social stress is discussed in relation to cognitive deficits and hippocampal changes that are observed in depressive patients. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.