These studies would indicate that the endogenous brain amines are responsive not only to LSD-25 and psychoactive congeners but also to some factor or factors of intense stress. If so, this would provide some biological link between psychoactive drugs, their effects upon amine metabolism and conditions which give rise to the need for such drugs. Perhaps, if endogenous amine mechanisms are chemically or genetically impaired, this could be reflected in altered psychophysiologic function in the face of excessive activation or demand.These studies refer largely to changes in the rat brain. If we are not to anthropomorphize the rat nor "rodentomorphize" man, our speculation must be limited. Within the rat some psychotomimetic drugs show a pattern of effects on biogenic amines and vice versa. There are little data for the rat which firmly link rates of binding and release within a specific animal with specific patterns of physiological or behavioral response. With respect to psychophysiological effects, these changes in amine levels could conceivably reflect an incidental rather than a necessary and sufficient response to the drug. Differential effects of drugs on amine levels are reliably observed, but for other than time of onset, the changes in levels have not been linked with the pattern of effects. We do not know if the similarity in pattern of amine response to certain stressors and to psychotomimetic drugs reflects similarities in mechanism. Thus, 8 years after Woolley's hypothesis, a relationship of LSD-25 to central amines and certain correlations of amines with autonomic and psychomotor function in the rat and in man can be demonstrated. The mechanisms accountable for these facts and their specific relationship to disturbed patterns of function have not been unraveled, even in the rat.Abstract Teaser