Distribution of neuropeptide Y immunoreactivity in the rat basal ganglia: effects of excitotoxin lesions to caudate-putamen.

ABSTRACT

The distribution of neuropeptide Y-like immunoreactivity (NPY-LI) within the rat basal ganglia was studied using microdissection with a sensitive radioimmunoassay, and excitotoxin lesions were made in an attempt to characterise the neurones containing NPY in this brain area. Immunoreactivity was unevenly distributed in the basal ganglia of control rats, with concentrations in the caudate-putamen (CP) and nucleus accumbens being appreciably higher than those found in the globus pallidus and substantia nigra (SN). Within the CP, immunoreactivity was concentrated in caudal and extreme rostral aspects. N-Methyl-D-aspartate lesions of the rostral CP significantly reduced immunoreactivity in this area, whilst levels in other regions of the basal ganglia were unaffected. Neurones containing NPY-LI are likely to be intrinsic to the CP and do not appear to project to the globus pallidus or SN.