An Autoradiographic Study on the Rat Neostriatal Dopamine Receptor Changes after 6-hydroxydopamine Injection into the Medial Prefrontal Cortex / 신경정신의학

ABSTRACT

The frontal cortex of rat is innervated by dopaminergic pathway(mesocortical pathway) arising from ventral tegmental area. Several studies have suggested that mesocortical dopaminergic neurons may modulate the function of dopaminergic neurons at subcortical sites. The effect of lesions of the dopaminergic nerve terminals in the medial prefrontal cortex of the rat on dopamine D1 and D2 receptors within the striatum and olfactory tubercle has been investigated. Bilateral 6-hydroxy-dopamine lesions were stereotaxically placed in the medial prefrontal cortex. Animal were pretreated with desipramine to block the uptake of neurotoxin into noradrenergic terminals and to make it more selective for dopamine terminal. After 2weeks later, we examined the changes of D1 and D2 receptors in caudate-putamen and nucleus accumbens by quantitative autoradiography using the specific D1 antagonist [3H]SCH23390 and D2 antagonist [3H]spiperone. The results shows that D1 receptor at striatum was up regulated 2weeks after destruction of dopamine terminals within medial prefrontal vortex of the rat. This findings suggest that frontal cortical dopamine system may regulate the dopamine system in corpus striatum.