A SUBSET OF STRIATOPALLIDAL NEURONS ARE FOS-IMMUNOPOSITIVE FOLLOWING ACUTE MONOAMINE DEPLETION IN THE RAT

Experiments were conducted to characterise the Fos-immunopositive neur ons that are observed in the dorsal rim of the striatum following mono amine depletion by the systemic administration of reserpine. Using a r etrograde tract-tracer, some of these neurons could be shown to projec t to the globus pallidus but none were seen to project to the entopedu ncular nucleus. In addition, these neurons were located in a region of both poor calbindin immunoreactivity and cholinesterase activity. It can be concluded that Fos levels are increased only in a subset of str iatopallidal neurons following monoamine depletion. This subset of neu rons is located in the dorsal region of the striatum where it has-prev iously been shown that neurons can preferentially be induced to underg o apoptosis upon monoamine depletion.