MODULATION OF MOTOR BEHAVIOR BY NMDA-ANTAGONISM AND CHOLECYSTOKININ-ANTAGONISM

Motor behaviour relies on complex neurochemical interactions in the ba sal ganglia, in particular the striatum. Antagonistic influences in th is region are exerted by afferent projections from, on the one hand, t he ventral mesencephalon, utilizing dopamine as a transmitter, and, on the other hand, from the cerebral cortex, signalling by the excitator y amino acid glutamate. The activity in both these neuronal population s appears to be regulated by the neuropeptide cholecystokinin. This ar ticle concentrates on interactions between cholecystokinin and glutama te, summarizing some recent morphological, biochemical and behavioural findings. It is suggested that cholecystokinin, acting via the cholec ystokinin(B) receptor, potentiates the glutamatergic excitatory input to the striatum.