Acetylcholine sensitivity of cat petrosal ganglion neurons

M. Shirahata, Y. Ishizawa, M. Rudisill, James Sham, B. Schofield, Robert S Fitzgerald

Research output: Contribution to journalArticle

Abstract

We investigated if neuronal nicotinic acetylcholine receptors (nAChRs) are localized in chemoreceptor afferent neurons in the cat petrosal ganglion (PG) and if acetylcholine (ACh) excites chemoreceptor afferent neurons. Immunocytochemistry revealed that a majority of PG neurons expressed α4 and/or α7 subunits of neuronal nAChRs, and a part of them were tyrosine hydroxylase positive. Excitability of cultured PG neurons was studied with patch clamp techniques (whole cell configuration). ACh and nicotine evoked both inward and outward currents. The inward current was partially blocked by removal of extracellular calcium and by antagonists for α4β2 (dihydro-β-erythroidine) or α7 nAChRs (methyllycaconitine). Outward current was blocked by 4-aminopyridine (4-AP) and sometimes by atropine. ACh-induced membrane potential changes were well correlated with ACh-induced currents. Depolarization and hyperpolarization occurred in response to ACh. Occasionally depolarization was followed by a train of action potentials. The results suggest that heterogeneous neuronal nAChRs are widely distributed in both chemoreceptor and other PG neurons. In some neurons nAChRs may be functionally, coupled with outward K+ channels. Further studies are required to determine whether chemoreceptor neurons have a distinct distribution pattern of nAChRs and K+ channels.

Original languageEnglish (US)
Pages (from-to)377-387
Number of pages11
JournalAdvances in Experimental Medicine and Biology
Volume475
StatePublished - 2000

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Keywords

  • Culture
  • Immunocytochemisry
  • Inward current
  • Membrane potential
  • Neuronal nicotinic acetylcholine receptor
  • Neurotransmitter
  • Outward current
  • Patch clamp

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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