CGRP IMMUNOREACTIVE NEURONS IN RAT DORSAL-ROOT GANGLIA DO NOT ALL CONTAIN LOW-AFFINITY NGF RECEPTOR IMMUNOREACTIVITY

Nerve growth factor (NGF) and its homologues bind to the low affinity NGF receptor (LNGFR). We have determined whether the LNGFR colocalizes with calcitonin gene-related peptide (CGRP) as this peptide is restri cted to neurons exhibiting high affinity binding sites for NGF. LNGFR and CGRP immunoreactivities were detected in 57% and 49% of spinal gan glion neurons respectively with different soma areas and only partial colocalization. Our data suggest that the LNGFR may not be essential f or a functional neurotrophin response.