| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Neurophysiol (May 1, 2003). 10.1152/jn.00934.2002
Submitted on Submitted 25 October 2002; accepted in final form 14 January 2003
Department of Pharmacology, George Washington University, Washington, DC 20037
Wang, Jijiang,
Xin Wang,
Mustapha Irnaten,
Priya Venkatesan,
Cory Evans,
Sunit Baxi, and
David Mendelowitz.
Endogenous Acetylcholine and Nicotine Activation Enhances
GABAergic and Glycinergic Inputs to Cardiac Vagal Neurons. J. Neurophysiol. 89: 2473-2481, 2003. The heart slows during expiration and heart rate increases during
inspiration. This cardiorespiratory interaction is thought to occur by
increased inhibitory synaptic events to cardiac vagal neurons during
inspiration. Since cholinergic receptors have been suggested to be
involved in this cardiorespiratory interaction, we tested whether
endogenous cholinergic activity modulates GABAergic and glycinergic
neurotransmission to cardiac vagal neurons in the nucleus ambiguus,
whether nicotine can mimic this facilitation, and we examined the
nicotinic receptors involved. Cardiac vagal neurons in the rat were
labeled with a retrograde fluorescent tracer and studied in an in vitro
slice using patch-clamp techniques. Application of neostigmine (10 µM), an acetylcholinerase inhibitor, significantly increased the
frequency of both GABAergic and glycinergic inhibitory postsynaptic
currents (IPSCs) in cardiac vagal neurons. Exogenous application of
nicotine increased the frequency and amplitude of both GABAergic and
glycinergic IPSCs. The nicotinic facilitation of both GABAergic and
glycinergic IPSCs were insensitive to 100 nM 
-bungarotoxin but were
abolished by dihydro-
-erythrodine (DHE) at a concentration (3 µM) specific for 42 nicotinic receptors. In the presence of
TTX, nicotine increased the frequency of GABAergic and glycinergic
miniature synaptic events, which were also abolished by DHE (3 µM). This work demonstrates that there is endogenous cholinergic
facilitation of GABAergic and glycinergic synaptic inputs to cardiac
vagal neurons, and activation of 42 nicotinic receptors at
presynaptic terminals facilitates GABAergic and glycinergic neurotransmission to cardiac vagal neurons. Nicotinic facilitation of
inhibitory neurotransmission to premotor cardiac parasympathetic neurons may be involved in generating respiratory sinus arrhythmia.
This article has been cited by other articles:
|
|
 |
|
  J. G. Frank, H. S. Jameson, C. Gorini, and D. Mendelowitz Mapping and Identification of GABAergic Neurons in Transgenic Mice Projecting to Cardiac Vagal Neurons in the Nucleus Ambiguus Using Photo-Uncaging J Neurophysiol, April 1, 2009; 101(4): 1755 - 1760. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Wang Nicotinic Receptors Partly Mediate Brainstem Autonomic Dysfunction Evoked by the Inhaled Anesthetic Isoflurane Anesth. Analg., January 1, 2009; 108(1): 134 - 141. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. G. Huang, K. J. S. Griffioen, X. Wang, O. Dergacheva, H. Kamendi, C. Gorini, and D. Mendelowitz Nicotinic Receptor Activation Occludes Purinergic Control of Central Cardiorespiratory Network Responses to Hypoxia/Hypercapnia J Neurophysiol, October 1, 2007; 98(4): 2429 - 2438. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Rowland, J. Rigby, A. C. Harper, and R. Rowland Cardiovascular monitoring with acetylcholinesterase inhibitors: a clinical protocol Adv. Psychiatr. Treat., May 1, 2007; 13(3): 178 - 184. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Bandyopadhyay, B. Sutor, and J. J. Hablitz Endogenous Acetylcholine Enhances Synchronized Interneuron Activity in Rat Neocortex J Neurophysiol, March 1, 2006; 95(3): 1908 - 1916. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z.-G. Huang, K. J. S. Griffioen, X. Wang, O. Dergacheva, H. Kamendi, C. Gorini, E. Bouairi, and D. Mendelowitz Differential Control of Central Cardiorespiratory Interactions by Hypercapnia and the Effect of Prenatal Nicotine J. Neurosci., January 4, 2006; 26(1): 21 - 29. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Padley, D. H. Overstreet, P. M. Pilowsky, and A. K. Goodchild Impaired cardiac and sympathetic autonomic control in rats differing in acetylcholine receptor sensitivity Am J Physiol Heart Circ Physiol, November 1, 2005; 289(5): H1985 - H1992. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Neff, S. J. Simmens, C. Evans, and D. Mendelowitz Prenatal Nicotine Exposure Alters Central Cardiorespiratory Responses to Hypoxia in Rats: Implications for Sudden Infant Death Syndrome J. Neurosci., October 20, 2004; 24(42): 9261 - 9268. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z.-G. Huang, X. Wang, C. Evans, A. Gold, E. Bouairi, and D. Mendelowitz Prenatal Nicotine Exposure Alters the Types of Nicotinic Receptors That Facilitate Excitatory Inputs to Cardiac Vagal Neurons J Neurophysiol, October 1, 2004; 92(4): 2548 - 2554. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. A. Neff, J. Wang, S. Baxi, C. Evans, and D. Mendelowitz Respiratory Sinus Arrhythmia: Endogenous Activation of Nicotinic Receptors Mediates Respiratory Modulation of Brainstem Cardioinhibitory Parasympathetic Neurons Circ. Res., September 19, 2003; 93(6): 565 - 572. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
