Cholinergic neurons are distributed preferentially in areas rich in substance P-like immunoreactivity in the caudate nucleus of the adult cat.
The distribution of cells stained immunocytochemically for the cholinergic marker choline acetyltransferase was compared to the pattern of substance P immunoreactivity in the caudate nucleus of adult cats using a double-label immunocytochemical protocol and three-dimensional reconstructions of adjacent sections single-labeled for either substance P or choline acetyltransferase. Substance P immunoreactivity was distributed in a highly complex mosaic within the caudate nucleus of the cat. In the dorsal caudate nucleus, substance P-rich zones consisting of either clusters of substance P-positive cell bodies or fibers were seen against a lighter staining background. The density of cholinergic neurons was found to be significantly greater within these substance P-rich patches in comparison to surrounding regions. The pattern of substance P immunoreactivity within the ventral caudate nucleus differed from that in more dorsal regions. Clear substance P-rich patches were not seen in this region, but a large substance P-rich area consisting of a dense plexus of substance P-containing fibers was visible. Embedded within this substance P-rich area were fairly discrete patches of light substance P staining. As in the dorsal caudate nucleus, increased numbers of cholinergic neurons and processes were associated with substance P-rich regions in the ventral caudate nucleus. Choline acetyltransferase-positive perikarya also appeared to be concentrated in substance P-rich areas in the nucleus accumbens and olfactory tubercle. The results of this study suggest that a close relationship exists between the distribution of substance P fibers and cholinergic perikarya in the striatum of the cat.
Martone
M E
ME
Department of Psychiatry, University of California, San Diego 92093-0603.
Armstrong
D M
DM
Young
S J
SJ
Groves
P M
PM
D000818:Animals; D015415:Biomarkers; D002415:Cats; D002421:Caudate Nucleus / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D009830:Olfactory Bulb / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D010275:Parasympathetic Nervous System / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D013194:Staining and Labeling; D013373:Substance P / Q000276:immunology / Q000378:metabolism*
D015415:Biomarkers; D013373:Substance P; D002795:Choline O-Acetyltransferase