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

Experiments were conducted to characterise the Fos-immunopositive neurons that are observed in the dorsal rim of the striatum following monoamine depletion by the systemic administration of reserpine. Using a retrograde tract-tracer, some of these neurons could be shown to project to the globus pallidus but none were seen to project to the entopeduncular 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 striatopallidal neurons following monoamine depletion. This subset of neurons is located in the dorsal region of the striatum where it has-previously been shown that neurons can preferentially be induced to undergo apoptosis upon monoamine depletion.