[The effect of electroconvulsive shock on central serotonin1A receptor function].
Effect of electroconvulsive shock (ECS) on central serotonin (5-HT) receptor function was studied in order to elucidate its antidepressive mechanism. Repeated ECS treatment, but not imipramine treatment, increased the density of [3H]8-hydroxy-2-(di-n-propylamino)tetraline ( [3H]8-OH-DPAT) binding in hippocampus, and enhanced 5-HT metabolism in all regions except hippocampus. Parachloroamphetamine (PCA), a neurotoxin of 5-HT neuron, did not affect the up-regulation of [3H]8-OH-DPAT binding (5-HT1A receptor) induced by ECS. These results suggest that presynaptic 5-HT terminal does not modulate the up-regulation of 5-HT1A receptor induced by ECS. In addition, 5-HT1A-receptor-mediated behavior (forepaw treading) was enhanced by repeated ECS treatment, but unchanged by imipramine treatment. The effect of ECS on 5-HT1A function is not parallel with that of imipramine, thus it is difficult to explain 5-HT1A receptor mainly contributes to the antidepressive effect of ECS. The above results suggested that the up-regulation of 5-HT1A receptor induced by repeated ECS treatment did not directly relate to presynaptic 5-HT function and other receptors might modify the effects of ECS.
Department of Psychiatry and Neuroscience, Kure National Hospital, Hiroshima, Japan.
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H
Hayakawa
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Yokota
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Yamawaki
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D004597:Electroshock; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*
D000928:Antidepressive Agents; D011985:Receptors, Serotonin; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D007099:Imipramine