Calcitonin gene-related peptide (CGRP)-immunoreactive nerve varicosities in synaptic contact with sensory neurons in the trigeminal ganglion of rats.

Immuno-light and -electron microscopic analyses revealed for the first time and reliably a substantial, although small, number of synapses between calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers and sensory neuron somata in the rat trigeminal ganglion. The CGRP-immunoreactive pericellular fibers forming the synapses survived the isolation and subsequent short-term incubation in the anterior eye chamber, indicating the intraganglionic origin of the pericellular fibers.