| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada A1B 3V6
In
urethan-anesthetized rats, esophageal distension evoked
volume-dependent reflex contractions with phase-locked multiunit discharges in the central subnucleus of the solitary tract complex (NTSC) and the nucleus ambiguus.
During blockade of solitarial, but not peripheral, muscarinic
cholinoceptors, the volume-response relationship of reflex contractions
was shifted rightward with a depression in pressure wave amplitude.
Concurrently, premotor NTSC
responses were attenuated and nucleus ambiguus activity was abolished
during esophagomotor inhibition. Both
NTSC discharges and reflex
responses were eliminated, or strongly inhibited, during blockade of
excitatory amino acid receptors (EAARs) with
6-cyano-7-nitroquinoxaline-2,3-dione, 
-glutamylglycine or
2-amino-7-phosphonoheptanoate. In brain stem slice preparations, whole
cell recordings in the NTSC region
revealed fast excitatory postsynaptic potentials (EPSPs) with spikes in response to electrical stimulation of the solitary tract. Although spiking was facilitated by muscarine, EPSPs were resistant to cholinoceptor antagonists but sensitive to EAAR blockers. We conclude that esophageal vagal afferents excite ipsilateral
NTSC interneurons via activation
of glutamate receptors of the
DL-
-amino-3-hydroxy-5-methylisoxazole-propionic acid and
N-methyl-D-aspartate
subtypes. Cholinergic input to the NTSC probably derives from
propriobulbar sources and serves to modulate the responsiveness of
reflex interneurons.
central subnucleus; nucleus ambiguus; acetylcholine; glutamate; nucleus of the solitary tract
This article has been cited by other articles:
|
|
 |
|
  G. E. Hermann, R. A. Travagli, and R. C. Rogers Esophageal-gastric relaxation reflex in rat: dual control of peripheral nitrergic and cholinergic transmission Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1570 - R1576. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Baptista, Z. L. Zheng, F. H. Coleman, R. C. Rogers, and R. A. Travagli Cholecystokinin Octapeptide Increases Spontaneous Glutamatergic Synaptic Transmission to Neurons of the Nucleus Tractus Solitarius Centralis J Neurophysiol, October 1, 2005; 94(4): 2763 - 2771. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Barnes, D. M. DeWeese, and M. C. Andresen Angiotensin potentiates excitatory sensory synaptic transmission to medial solitary tract nucleus neurons Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2003; 284(5): R1340 - R1353. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Zheng, C. Patterson, and H.-R. Berthoud Behavioral analysis of anorexia produced by hindbrain injections of AMPA receptor antagonist NBQX in rats Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2002; 282(1): R147 - R155. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Dong, C. W. Loomis, and D. Bieger Vagal afferent input determines the volume dependence of rat esophageal motility patterns Am J Physiol Gastrointest Liver Physiol, July 1, 2001; 281(1): G44 - G53. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Hornby Receptors and Transmission in the Brain-Gut Axis: II. Excitatory amino acid receptors in the brain-gut axis Am J Physiol Gastrointest Liver Physiol, June 1, 2001; 280(6): G1055 - G1060. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Jean Brain Stem Control of Swallowing: Neuronal Network and Cellular Mechanisms Physiol Rev, April 1, 2001; 81(2): 929 - 969. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Sang and R. K. Goyal Swallowing reflex and brain stem neurons activated by superior laryngeal nerve stimulation in the mouse Am J Physiol Gastrointest Liver Physiol, February 1, 2001; 280(2): G191 - G200. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
