Studies on the coexistence of substance P with other putative transmitters in the nodose and petrosal ganglia

Synapse. 1990;5(2):144-51. doi: 10.1002/syn.890050209.


Visceral afferent neurons of the nodose and petrosal ganglia are immunoreactive (ir) for many neurotransmitters [e.g., substance P (SP), neurokinin A (NKA), calcitonin gene-related peptide (CGRP), and dopamine (tyrosine hydroxylase-ir; TH)]. Coexistence of SP-ir with NKA-, CGRP-, or TH-ir was studied in individual neurons of the rat ganglia using fluorescence immunocytochemistry. SP- and NKA-ir were present in equal numbers of cells and were consistently colocalized. SP- and CGRP-ir were found to be similarly distributed in scattered cells, concentrated mostly in the rostral pole of the nodose ganglion and in the petrosal ganglion. SP-ir completely coexisted with CGRP-ir. However, there was at least twice the number of CGRP-ir neurons as SP-ir neurons, and thus CGRP-ir neurons that did not contain SP-ir were also present. In contrast, SP- and TH-ir had different distributions in both the nodose and the petrosal ganglia. SP-ir was located in the more rostral regions of both the nodose and petrosal ganglia, whereas TH-ir was detected throughout the entire nodose ganglion and only in the most caudal region of the petrosal ganglion. There was no coexistence of SP- and TH-ir. These data demonstrate the differential localization and coexistence of putative transmitters in visceral sensory neurons in the nodose and petrosal ganglia.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcitonin Gene-Related Peptide / metabolism*
  • Glossopharyngeal Nerve / cytology
  • Glossopharyngeal Nerve / metabolism*
  • Immunohistochemistry
  • Male
  • Neurokinin A / metabolism*
  • Nodose Ganglion / cytology
  • Nodose Ganglion / metabolism*
  • Rats
  • Rats, Inbred Strains
  • Substance P / metabolism*
  • Tyrosine 3-Monooxygenase / metabolism
  • Vagus Nerve / metabolism*


  • Substance P
  • Neurokinin A
  • Tyrosine 3-Monooxygenase
  • Calcitonin Gene-Related Peptide