Diazepam produces regionally specific effects on brain serotonin metabolism in rats

ABSTRACT

In view of a possible role of serotonin in anxiety, the effect of low doses [1mg/kg] of diazepam on brain regional levels of tryptophan, 5 - hydroxytryp - tamine [5 -HT] and 5 - hydroxyindoleacetic acid [5 - HIAA] are investigated in rats. The concentration of tryptophan increased in the hippocampus, hypothalamus, striatum and cortex; increases in the brain stem were not significant. The concentration of 5 - HT decreased in the hippocampus, increased in the hypothalamus and cortex and cortex and remained unaltered in the striatum and brain stem. 5 - HIAA concentration decreased in the hypothalamus, increased in the striatum and remained unaltered in the hippocampus, cortex and brain stem. Possible mechanism involved in the regionally specific effects of diazepam - induced changes of brain 5 - HT metabolism and their functional significance is discussed