THE CORTICOSTRIATAL PROJECTION - FROM SYNAPTIC PLASTICITY TO DYSFUNCTIONS OF THE BASAL GANGLIA

Corticostriatal transmission has an important function in the regulati on of the neuronal activity of the basal ganglia. The firing activity of corticostriatal neurones excites striatal cells via the release of glutamate. Presynaptic receptors that ave located on corticostriatal t erminals and that regulate the release of glutamate in the striatum ha ve been postulated for dopamine and glutamate. Activation of these rec eptors may exert a negative feed-back on the striatal release of gluta mate. High-frequency activation of corticostriatal fibres causes eithe r long-term depression or long-term potentiation of excitatory transmi ssion depending on the subclass of glutamate receptor that is activate d. These forms of synaptic plasticity could be involved in motor learn ing. Alterations in striatal synaptic plasticity might be implicated i n Parkinson's disease and Huntington's disease.