Acetylcholine activates a nicotinic receptor and an inward current in dorsal motor nucleus of the vagus neurons in vitro.
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.
Neff
R A
RA
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163, USA.
Hansen
M K
MK
Mendelowitz
D
D
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*
D018721:Muscarinic Agonists; D018722:Nicotinic Agonists; D015221:Potassium Channels; D011978:Receptors, Nicotinic; D018723:Bethanechol; D009538:Nicotine; D000109:Acetylcholine