Central neurotransmitter function and its behavioral correlates in man.

The past decade has witnessed a tremendous increase in knowledge towards understanding the function of various brain neurotransmitter substances in behavior. Experimental observations in animals, utilizing specific pharmacological agents, have enabled the development of certain hypotheses regarding neurochemical substrates of behavior. These have led to cautious applications of complementary studies in humans. As a result, several neurotransmitter-related hypotheses have been developed for the explanation of normal behaviour, as well as of various abnormal behavior states in psychiatry and neurology. These hypotheses are currently undergoing extensive investigation. Highlights of the above sequence of events are presented, in order to provide as general, yet extensive, an overview of the subject as possible. Examples are provided from both basic laboratory investigations and from clinical findings. Principles of brain neurotransmitter function and interactions are reviewed. Various neurotransmitter-related hypothese of psychiatric and neurologic interest are introduced. Finally, the role that toxicants may have on behavior via alteration of brain neurotransmitter function is discussed, using the lead intoxicated animals as an illustrative example.