Serotonin (5-hydroxytryptamine, 5-HT) has been implicated in the pathophysiology of many neuropsychiatric disorders, and alcohol is reported to influence serotonergic neuronal activity in the dorsal raphe. In the present study, the effects of ethanol on the synthesis of 5-HT and the expression of tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT synthesis, in the dorsal and median raphe of rats were investigated, using immunohistochemical methods. Results showed that the density of 5-HT-positive and TPH-positive cells was reduced by ethanol treatment in a time-dependent manner. Based on these results, it is suggested that the pathogenesis of ethanol-induced neuropsychological disorders involves ethanol-induced suppression of 5-HT synthesis and TPH expression in the raphe region.
- Tryptophan hydroxylase
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