Immunocytochemical localization of the low-affinity nerve growth factor receptor (p75 NGFR) in the cuneate nucleus of the rat and its relationship to cytochrome-oxidase activity

Immunohistochemical staining for the 75-kDa, low-affinity nerve growth factor receptor (p75 NGFR), within the cuneate nucleus (CN) of the adult rat revealed that this receptor is concentrated rostrocaudally in the middle CN (approximately 0.2–0.9 mm caudal to the obex), corresponding to that portion of the CN receiving densest projections of cutaneous primary afferent terminals. Furthermore, dense patches of p75 NGFR-like immunoreactivity appear to correspond to the ‘blotches’ of cytochrome-oxidase activity observed in the middle region of the CN. This close correspondence between the localization pattern of p75 NGFR in the CN and its functional organization suggests an important role for trophic factors in the CN's development and/or maintenance.