The mutability of low-affinity nerve growth factor receptor (p75^NGFR) expression in the rat cuneate nucleus following perinatal injury and adult deafferentations: comparisons with cytochrome oxidase

In normal adult rats, intense immunostaining for the 75 kDa low-affinity receptor for nerve growth factor and other neurotropins (p75^NGFR) is concentrated in the middle region of the cuneate nucleus (CN), distributed in a blotchy pattern similar to that of cytochrome oxidase (CO) activity. In the adult rats, partial dorsal rhizotomies (centered around the 7th and 8th cervical spinal segments) resulted in the complete disappearance of p75^NGFR-like immunoreactivity within the ipsilateral CN, but did not affect the distribution of the CO blotches. Perinatal (postnatal day 1-8) damage to the ipsilateral forepaw and subsequent rearing to adulthood also resulted in significant disruption of the topographical expresion of p75^NGFR-like immunoreactivity within the CN, as well as - as previously reported - disruption of the CO blotches. Although the patterns of staining in intact adult rats are similar for CO staining and for p75^NGFR-like immunoreactivity within the CN, the CO staining appears to be primarily associated with postsynaptic cells, while the p75^NGFR-like immunostaining appears to be associated with primary afferent terminals.