Chronic effects of mianserin on noradrenaline metabolism in the rat brain: evidence for a pre-synaptic alpha-adrenolytic action in vivo.

Chronic administration of the pre-synaptic alpha-adrenoreceptor agonist clonidine decreases the concentration of the extra-neuronal metabolite of noradrenaline normetanephrine in the amygdaloid cortex and increases it in the mid-brain. Conversely, blockade of these pre-synaptic receptors by yohimbine increases the normetanephrine concentration in the amygdaloid cortex and decreases it in the mid-brain. Mianserin had a qualitatively similar action to that of yohimbine.