title: Acetylcholine activates a nicotinic receptor and an inward current in dorsal motor nucleus of the vagus neurons in vitro.
abstract: This study examines the effect of acetylcholine (Ach) on parasympathetic vagal neurons in the dorsal motor nucleus of the vagus (DMNX). Patch-clamp techniques were utilized to examine voltage and ligand-gated currents in visualized DMNX neurons in an in vitro slice. Ach (100 microM) activated an inward current, -196.4 +/- 56.9 pA at -80 mV (n = 15) that was accompanied by a decrease in membrane resistance of 48.6 +/- 9.2% in a population of DMNX neurons. The reversal potential for this ligand-gated current was -11.3 +/- 11.5 mV. The specific agonist nicotine (200 microM) elicited similar responses. Nicotine decreased membrane resistance by 60.9 +/- 4.3% and activated an inward current (-215.7 +/- 45.7 pA at -80 mV) that reversed at -12.7 +/- 20.4 mV (n = 16). Bethanecol (100 microM), a specific muscarinic agonist, had no effect. Neither Ach or nicotine had any effect on the voltage-gated sodium and outward potassium currents present in these neurons.
authors.affiliation: Department of Physiology and Biophysics, University of Tennessee, Memphis 38163, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Neff
authors.forename: M K
authors.initials: MK
authors.lastname: Hansen
authors.forename: D
authors.initials: D
authors.lastname: Mendelowitz
mesh_terms: D000109:Acetylcholine / Q000502:physiology*; D000818:Animals; D018723:Bethanechol / Q000494:pharmacology; D008564:Membrane Potentials / Q000502:physiology; D009046:Motor Neurons / Q000502:physiology* / Q000648:ultrastructure; D018721:Muscarinic Agonists / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000502:physiology*; D014630:Vagus Nerve / Q000166:cytology / Q000502:physiology*
chemical_list: D018721:Muscarinic Agonists; D018722:Nicotinic Agonists; D015221:Potassium Channels; D011978:Receptors, Nicotinic; D018723:Bethanechol; D009538:Nicotine; D000109:Acetylcholine