Calcitonin gene-related peptide and neuropeptide Y in the raccoon cuneate nucleus

Immunocytochemical methods were used to determine the distribution of calcitonin gene-related peptide (CGRP) and neuropeptide Y (NPY) in the middle region of the adult raccoon cuneate nucleus. Extensive CGRP-immunoreactive fibers and darkly stained punctate structures, thought to be terminals, were concentrated in the dorsal cap and basal region of the middle cuneate nucleus. These regions receive input from the claws and the hairy skin of the paw and forearm. The NPY-immunoreactive fibers and terminals were also found within the dorsal cap of the cuneate nucleus, but were less abundant than CGRP. However, most of the NPY-immunostained fibers and terminals were found in the cluster region of the cuneate nucleus, which receives input from glabrous skin. No CGRP- or NPY-immunoreactive cell bodies were found in the raccoon middle cuneate nucleus. This description of the distribution of CGRP and NPY in the normal animal provides a baseline for future investigations into injury-induced neuropeptide plasticity in the raccoon middle cuneate nucleus.