Excitotoxic lesions of the prefrontal cortex reduce dopamine D-1-like receptors in the ventral tegmental area

Ventral mesencephalic dopamine D-1-like receptors were quantified in brains of male rats ten days after unilateral microinjections of ibotenic acid (2 or 10 mu g/mu l) or its vehicle into the medial prefrontal cortex. The density of dopamine D-1-like receptors was reduced by more than 40% in the ipsilateral ventral tegmental area (both doses) and by 15% (low dose) and 44% (high dose) in the contralateral side; no significant reduction was observed in the substantia nigra. These results suggest that a significant number of ventral tegmental D-1-like receptors are localized on afferent terminals from the medial prefrontal cortex. (C) 1997 Elsevier Science B.V.