[3H]Dopamine release in striatum in response to cortical stimulation in a corticostriatal slice preparation

A new method has been developed to investigate corticostriatal glutamatergic influence on [3H]dopamine release in striatum in complex corticostriatal slice preparation in vitro. Horizontal slices containing the striatum and the adjacent prefrontal cortex of rat brain were cut in a plane that maintains corticostriatal connections. After incubation with [3H]dopamine, slices were submerged in a two-compartment bath so that the cortical region was contained entirely in one compartment, corpus callosum passed through a silicone greased slot, and the striatal region was contained in the other compartment. A cannula was placed just above the striatal part of the slice and effluent was collected with a peristaltic pump, released tritiated materials were counted with a liquid scintillation counter. Electric field stimulation of cortex increased the release of [3H]dopamine in the striatum. Bicuculline (1 mM) increased the basal and stimulated release of [3H]dopamine in the striatum in response to cortical stimulation of cortex indicating the GABAergic control on dopamine release. This method allows investigation of the effect of cortical stimulation on glutamate-dopamine-GABA interactions in the striatum in vitro that might help to understand better the neurochemical background of schizophrenia or Parkinson's disease.