 |
 Previous Article | Next Article 
Journal of Neuroscience, Vol 9, 1910-1921, Copyright © 1989 by Society for Neuroscience
Involvement of excitatory amino acids in neurotransmission of inspiratory drive to spinal respiratory motoneurons
DR McCrimmon, JC Smith and JL Feldman
Department of Physiology, Northwestern University Medical School, Chicago, Illinois 60611.
The role of excitatory amino acids in the transmission of bulbospinal
respiratory drive to spinal motoneurons was investigated in the in vitro
and in vivo spinal cord of the rat. In vitro studies were performed with a
preparation of neonatal rat brain stem and spinal cord that spontaneously
generates rhythmic respiratory drive to spinal respiratory motoneurons.
This in vitro system allowed examination of the effects of pharmacological
agents on spinal motoneuron activity, without perturbing the activity of
bulbospinal neurons transmitting the respiratory drive. The amplitude of
spontaneous motor discharge in spinal ventral roots containing phrenic and
intercostal motor axons was reduced in a dose-dependent manner by
antagonists to excitatory amino acids acting at NMDA receptors
[D,L-2-amino-5-phosphonovaleric acid (D,L-AP5)] and non-NMDA receptors
[kynurenic acid, gamma-D- glutamylglycine, gamma-D-glutamyltaurine, and L-
and D,L-2-amino-4- phosphonobutyric acid (L-AP4,D,L-AP4)]. The order of
potency of the antagonists for complete block of the motor output was L-AP4
greater than D,L-AP4 greater than kynurenic acid greater than gamma-D-
glutamylglycine greater than D,L-AP5 greater than or equal to gamma-D-
glutamyltaurine. Amino acid uptake inhibitors augmented the spontaneous
motoneuron activity, further confirming the involvement of endogenous
excitatory amino acids in transmission of respiratory drive. The results
obtained in vitro with AP4, kynurenic acid, and amino acid uptake
inhibitors were confirmed in vivo by bathing segments of the rat spinal
cord in situ with solutions containing antagonists and uptake inhibitors.
The present results suggest that an important component of the
neurotransmission of bulbospinal respiratory drive involves endogenous
excitatory amino acids acting at AP4-sensitive sites and other non-NMDA
(quisqualate/kainate) receptors. The bulbospinal-spinal respiratory
motoneuron synapse may provide a convenient model synapse in the spinal
cord for detailed analysis of mechanisms underlying excitatory amino
acid-mediated synaptic transmission of motor drive.
This article has been cited by other articles:
|
|
|
|
 
M. McGuire, C. Liu, Y. Cao, and L. Ling
Formation and maintenance of ventilatory long-term facilitation require NMDA but not non-NMDA receptors in awake rats
J Appl Physiol,
September 1, 2008;
105(3):
942 - 950.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. W. Steenland, H. Liu, and R. L. Horner
Endogenous Glutamatergic Control of Rhythmically Active Mammalian Respiratory Motoneurons In Vivo
J. Neurosci.,
July 2, 2008;
28(27):
6826 - 6835.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. F. Ireland, F. C. Lenal, A. R. Lorier, D. E. Loomes, T. Adachi, T. S. Alvares, J. J. Greer, and G. D. Funk
Distinct receptors underlie glutamatergic signalling in inspiratory rhythm-generating networks and motor output pathways in neonatal rat
J. Physiol.,
May 1, 2008;
586(9):
2357 - 2370.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. R. McCrimmon and G. F. Alheid
On the opiate trail of respiratory depression
Am J Physiol Regulatory Integrative Comp Physiol,
December 1, 2003;
285(6):
R1274 - R1275.
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. G. Goshgarian
Plasticity in Respiratory Motor Control: Invited Review: The crossed phrenic phenomenon: a model for plasticity in the respiratory pathways following spinal cord injury
J Appl Physiol,
February 1, 2003;
94(2):
795 - 810.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. L. Jordan, S. E. Christensen, R. J. Handa, J. L. Anderson, W. A. Pouliot, and S. M. Breedlove
Evidence That Androgen Acts Through NMDA Receptors to Affect Motoneurons in the Rat Spinal Nucleus of the Bulbocavernosus
J. Neurosci.,
November 1, 2002;
22(21):
9567 - 9572.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. C. Rekling, G. D. Funk, D. A. Bayliss, X.-W. Dong, and J. L. Feldman
Synaptic Control of Motoneuronal Excitability
Physiol Rev,
April 1, 2000;
80(2):
767 - 852.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
X.-W. Dong and J. L. Feldman
Distinct Subtypes of Metabotropic Glutamate Receptors Mediate Differential Actions on Excitability of Spinal Respiratory Motoneurons
J. Neurosci.,
July 1, 1999;
19(13):
5173 - 5184.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Hilaire and B. Duron
Maturation of the Mammalian Respiratory System
Physiol Rev,
April 1, 1999;
79(2):
325 - 360.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
X.-W. Dong, D. Morin, and J. L. Feldman
Multiple Actions of 1S,3R-ACPD in Modulating Endogenous Synaptic Transmission to Spinal Respiratory Motoneurons
J. Neurosci.,
August 15, 1996;
16(16):
4971 - 4982.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Smith, H. Ellenberger, K Ballanyi, D. Richter, and J. Feldman
Pre-Botzinger complex: a brainstem region that may generate respiratory rhythm in mammals
Science,
November 1, 1991;
254(5032):
726 - 729.
[Abstract]
[PDF]
|
|
|
|
.gif?ad=17923&adview=true)
