Changes in brain monoamine content and metabolism induced by paraoxon and soman intoxication. Effect of atropine

1. Soman induced a decrease in hypothalamic, hippocampal and cortical noradrenaline, an increase in hippocampal and cortical dopamine and an increase in hypothalamic serotonin while paraoxon did not modify these neurotransmitter concentrations. The increases in 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindole acetic acid produced by the two drugs witness an accelerated turnover of dopamine and serotonin. 2. Atropine pretreatment completely antagonized the paraoxon-induced changes but only partially suppressed the soman-induced modifications. 3. These data suggest that soman produces a direct effect on monoamine metabolism which is not related to acetylcholine accumulation.