Coexistence of S100β and putative transmitter agents in vagal and glossopharyngeal sensory neurons of the rat

The coexistence of S100β 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. S100β immunoreactive (-ir) neurons in the jugular and petrosal ganglia frequently colocalized CGRP- or SP-ir, whereas S100β-ir neurons in the nodose ganglion infrequently contained CGRP- or SP-ir. No S100β-ir neurons in the jugular and petrosal ganglia showed SOM-ir while the small number of SOM-ir neurons in the nodose ganglion colocalized S100β-ir. Many neurons in the nodose ganglion colocalized S100β-ir and NADPH-d activity, whereas S100β-ir neurons in the jugular and nodose ganglia infrequently contained NADPH-d activity. S100β- and TH-ir were frequently colocalized in nodose ganglion but not in petrosal or jugular ganglion neurons. These findings suggest relationships between S100β and specific putative transmitters in functions of subpopulations of vagal and glossopharyngeal sensory neurons.