CO-EXPRESSION OF ALPHA-CGRP AND BETA-CGRP MESSENGER-RNAS IN THE RAT DORSAL-ROOT GANGLION-CELLS

We examined the expression of α-calcitonin gene-related peptide (α-CGRP) and β-CGRP mRNAs in the rat dorsal root ganglion (DRG) using in situ hybridization histochemistry with oligonucleotide probes. Analysis of autoradiograms showed that α-CGRP mRNA labeled 36.4% of all DRG neurons and β-CGRP mRNA labeled 30.8%. Small and medium-sized neurons expressed both types of mRNA, but large neurons showed a predominance of α-CGRP mRNA expression. The colocalization of α-CGRP and β-CGRP mRNAs was shown at a cellular level in consecutive DRG sections. Thus, we demonstrated that α-CGRP and β-CGRP were distributed differently in the DRG neurons, although genes coding for these neuropeptides coexist in the small or medium-sized neurons. © 1990.