Journal of Neuroscience, Vol 11, 828-836, Copyright © 1991 by Society for Neuroscience
Medial-to-lateral gradient of neostriatal NGF receptors: relationship to cholinergic neurons and NGF-like immunoreactivity
CA Altar, M Dugich-Djordjevic, M Armanini and C Bakhit
Developmental Biology, Genentech, Incorporated, South San Francisco, California 94080.
High-affinity binding sites for recombinant human NGF (rhNGF) were studied
in the caudate-putamen of the adult rat and rabbit. Displaceable 125I-rhNGF
binding sites were densely distributed throughout the caudate-putamen and
were 2-3-fold more prevalant in the ventrolateral and lateral than in the
medial caudate-putamen. The amount of nondisplaceable binding did not vary
throughout the caudate- putamen. The medial-to-lateral receptor gradient
was correlated (r = +0.99) with a 2-3-fold medial-to-lateral increase in
ChAT activity. In contrast, NGF-like immunoreactivity (NGF-LI) was
prevalent but uniformly distributed in the caudate-putamen. Lesions of
intrinsic cholinergic neurons by quinolinic acid produced extensive gliosis
in the medial, central, and lateral caudate-putamen, yet 125I-rhNGF binding
was decreased in each of these regions. The activity of ChAT and 125I-rhNGF
binding throughout the caudate-putamen were each decreased by 40% following
quinolinic acid. Binding was not changed after 70-77% dopamine nerve
terminal depletions induced by 6- hydroxydopamine, demonstrating a
nonglial, nondopaminergic locus for striatal NGF binding sites. The
cholinergiclike topography of NGF binding sites throughout the intact
caudate-putamen, the parallel decreases of cholinergic neurons and NGF
binding sites following intrinsic neuronal loss, and the uniform
neostriatal gradient of NGF-LI are consistent with the trophic role of
endogenous NGF for cholinergic interneurons of the caudate-putamen.