Calcitonin gene-related peptide (CGRP)-immunoreactive neurons in the human cervico-thoracic paravertebral ganglia.

The occurrence of CGRP-immunoreactive neurons in human paravertebral sympathetic ganglia was investigated and CGRP-immunoreactive perikarya correlated with the distribution of structures which were immunoreactive to other peptides and tyrosine hydroxylase, the key enzyme of catecholamine-synthesis. CGRP-immunoreactive neurons were present in all investigated ganglia (superior cervical ganglion, stellate ganglion, thoracic ganglia IV and VII). Most of the CGRP-immunolabelled cell bodies contained also vasoactive intestinal polypeptide-as well as somatostatin-immunoreactivity. Approximately 40 per cent of the CGRP-immunoreactive neurons were weakly tyrosine hydroxylase-immunolabelled. CGRP-immunoreactive cell bodies appear to be neither identical with the large population of neuropeptide Y-labelled perikarya nor with the large group of cell bodies which were surrounded by leuenkephalin-immunoreactive nerve fibres. Colocalization of CGRP- with vasoactive intestinal polypeptide- and somatostatin-immunoreactivity in postganglionic sympathetic neurons substantiates the suggestion of sympathetic origin of respective peptidergic nerve fibres in sweat glands.