Potentiation of 5-HT(3) receptor functions in the hippocampal CA1 region of rats following repeated electroconvulsive shock treatments.
Modulation of serotonin (5-HT)(3)-receptor function by repeated electroconvulsive shock (ECS) treatment was investigated to elucidate the mechanism underlying the effectiveness of electroconvulsive therapy (ECT) which is clinically used for drug-resistant depression. ECS (100 V, 1 s) was applied once a day for 14 days via an electrode placed on the ears of rats (ECS group). For controls, rats were handled similar to the ECS-treated group except for the stimulation. Hippocampal slices (thickness, 450 microm) were prepared 24 h after the final ECS treatment when rats were 5-6 weeks old. Intracellular recordings were made from the neurons in the CA1 pyramidal cell layer. Activation of 5-HT(3) receptors increased spontaneous postsynaptic potentials (sPSP). Increased sPSP was mainly mediated by GABA. The 5-HT(3) receptor mediated increase in sPSP was potentiated in the ECS group compared with the control group. These findings suggest that the 5-HT(3) receptor function is potentiated by repeated ECS.
Ishihara
K
K
Department of Pharmacotherapy, Graduate School of Medical Sciences, Hiroshima University, Hiroshima 734-8551, Japan. ishihara@pharm.hiroshima-u.ac.jp
Sasa
M
M
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D003863:Depression / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D004565:Electroconvulsive Therapy; D004597:Electroshock; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D044406:Receptors, Serotonin, 5-HT3; D012701:Serotonin / Q000378:metabolism / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D011985:Receptors, Serotonin; D044406:Receptors, Serotonin, 5-HT3; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin