Brain chemistry and behaviour.

The functional organization of chemically transmitting synapses in the brain are described with special emphasis on recent studies demonstrating the localization of different transmitters to specific anatomical circuitries. The use of pharmacological tools for manipulating levels of chemical transmitters is referred to briefly, but particular attention is given to the problems of studying the function of these pathways with lesion techniques. Noradrenaline (NA) and dopamine (DA) are selected for detailed consideration and experimental evidence reviewed, suggesting that these two catecholamines in the forebrain serve different functions: NA with processes of attention essential for learning, and DA with the execution of appropriate responses. Hypotheses suggesting dysfunction of forebrain DA and NA systems in schizophrenia are discussed.