[Psychopharmacology and neurohumoral transmission].

The authors remind neurobiologists that, if it is necessary to analyze the mechanisms of neurotransmission, it is altogether necessary to integrate them in a circuit. If there is e.g. a noradrenergic transmission, there is neither a noradrenergic function nor a noradrenergic system. Moreover, the same neurone may release different transmittors; the response of the effector depends on its level of excitability; the identification of a mediator--especially in the urine--does not tell how its activity is modulated etc. A few examples are given.