COMPARTMENTS IN RAT DORSAL AND VENTRAL STRIATUM REVEALED FOLLOWING INJECTION OF 6-HYDROXYDOPAMINE INTO THE VENTRAL MESENCEPHALON

The catecholamine selective neurotoxin, 6-hydroxydopamine, was injected into the ventral mesencephalon of rats and the distribution of tyrosine hydroxylase immunoreactivity in the striatum was compared to that of substance P and calbindin immunoreactivities, recognized histochemical markers of striatal compartments. Two components of the TH-IR mesostriatal innervation were identified. A more vulnerable component, present in the core of the nucleus accumbens and matrix of the caudate-putamen, excepting its ventrolateral part, was eliminated rapidly, unmasking a less vulnerable component which was present primarily in the shell of the nucleus accumbens and patch(striosome) compartment of the caudate-putamen. The TH-IR innervation in the ventrolateral caudate-putamen also was patchy following these lesions but the patches corresponded consistently to neither patch nor matrix compartments.