Coexistence of S100 β and putative transmitter agents in vagal and glossopharyngeal sensory neurons of the rat

The coexistence of S100 β with calcitonin gene-related peptide (CGRP), substance P (SP), somatostatin (SOM), nicotinamide adenosine dinucleotide phosphate-diaphorase (NADPH-d), and tyrosine hydroxylase (TH) was examined in the glossopharyngeal and vagal sensory ganglia. S100 β immunoreactive (-ir) neurons in the jugular and petrosal ganglia frequently colocalized CGRP- or SP-ir, whereas S100 β-ir neurons in the nodose ganglion infrequently contained CGRP- or SP-ir. No S100 β-ir neurons in the jugular and petrosal ganglia showed SOM-ir while the small number of SOM-ir neurons in the nodose ganglion colocalized S100 β-ir. Many neurons in the nodose ganglion colocalized S100 β-ir and NADPH-d activity, whereas S100 β-ir neurons in the jugular and nodose ganglia infrequently contained NADPH-d activity. S100 β- and TH-ir were frequently colocalized in nodose ganglion but not in petrosal or jugular ganglion neurons. These findings suggest relationships between S100 β and specific putative transmitters in functions of subpopulations of vagal and glossopharyngeal sensory neurons.