Nicotinic excitation of rat hypoglossal motoneurons

N. L. Chamberlin, C. M. Bocchiaro, R. W. Greene, J. L. Feldman

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Hypoglossal motoneurons (HMNs), which innervate the tongue muscles, are involved in several important physiological functions, including the maintenance of upper airway patency. The neural mechanisms that affect HMN excitability are therefore important determinants of effective breathing. Obstructive sleep apnea is a disorder characterized by recurrent collapse of the upper airway that is likely due to decline of pharyngeal motoneuron activity during sleep. Because cholinergic neuronal activity is closely coupled to wake and sleep states, we tested the effects and pharmacology of nicotinic acetylcholine receptor (nAChR) activation on HMNs. We made intracellular recordings from HMNs in medullary slices from neonatal rats and found that local application of the nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium iodide, excited HMNs by a Ca2+-sensitive, and TTX-insensitive inward current that was blocked by dihydro-β-erythroidine (IC50: 19±3 nM), methyllycaconitine (IC50: 32±7 nM), and mecamylamine (IC50: 88±11 nM), but not by α-bungarotoxin (10 nM). This is consistent with responses being mediated by postsynaptic nAChRs that do not contain the α7 subunit. These results suggest that nAChR activation may contribute to central maintenance of upper airway patency and that the decline in firing rate of cholinergic neurons during sleep could potentially disfacilitate airway dilator muscle activity, contributing to airway obstruction.

Original languageEnglish (US)
Pages (from-to)861-870
Number of pages10
JournalNeuroscience
Volume115
Issue number3
DOIs
StatePublished - Dec 9 2002

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Motor Neurons
Inhibitory Concentration 50
Sleep
Nicotinic Receptors
Maintenance
Nicotinic Agonists
Mecamylamine
Bungarotoxins
Muscles
Cholinergic Neurons
Iodides
Obstructive Sleep Apnea
Airway Obstruction
Tongue
Cholinergic Agents
Respiration
Pharmacology

Keywords

  • Genioglossus
  • Nicotinic/pharmacology
  • Pharyngeal dilator
  • Respiratory
  • Sleep apnea
  • Upper airway muscle

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Chamberlin, N. L., Bocchiaro, C. M., Greene, R. W., & Feldman, J. L. (2002). Nicotinic excitation of rat hypoglossal motoneurons. Neuroscience, 115(3), 861-870. https://doi.org/10.1016/S0306-4522(02)00454-2

Nicotinic excitation of rat hypoglossal motoneurons. / Chamberlin, N. L.; Bocchiaro, C. M.; Greene, R. W.; Feldman, J. L.

In: Neuroscience, Vol. 115, No. 3, 09.12.2002, p. 861-870.

Research output: Contribution to journalArticle

Chamberlin, NL, Bocchiaro, CM, Greene, RW & Feldman, JL 2002, 'Nicotinic excitation of rat hypoglossal motoneurons', Neuroscience, vol. 115, no. 3, pp. 861-870. https://doi.org/10.1016/S0306-4522(02)00454-2
Chamberlin, N. L. ; Bocchiaro, C. M. ; Greene, R. W. ; Feldman, J. L. / Nicotinic excitation of rat hypoglossal motoneurons. In: Neuroscience. 2002 ; Vol. 115, No. 3. pp. 861-870.
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