| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Journal of Neurophysiology, Vol 73, Issue 3 1013-1019, Copyright © 1995 by APS
ARTICLES |
R. Perrins and A. Roberts
School of Biological Sciences, University of Bristol, United Kingdom.
1. We have investigated whether in Xenopus embryos, spinal interneurons of the central pattern generator (CPG) receive cholinergic or electrical excitatory input during swimming. The functions of cholinergic excitation during swimming were also investigated. 2. Intracellular recordings were made from rhythmically active presumed premotor interneurons in the dorsal third of the spinal cord. After locally blocking inhibitory potentials with 2 microM strychnine and 40 microM bicuculline, the reliability of spike firing and the amplitude of fast, on-cycle, excitatory postsynaptic potentials (EPSPs) underlying the single on-cycle spikes were measured during fictive swimming. 3. The nicotinic antagonists d-tubocurarine and dihydro-beta-erythroidine (DH beta E, both 10 microM) reversibly reduced the reliability of the spike firing during swimming and reduced the amplitude of the on-cycle EPSP by 16%. DH beta E also reduced the EPSP amplitude in spinalized embryos by 22%. These results indicate that interneurons receive rhythmic cholinergic excitation from a source within the spinal cord. 4. Combined applications of nicotinic and excitatory amino acid (EAA) antagonists or cadmium (Cd2+, 100-200 microM) resulted in complete block of the fast EPSP, suggesting that interneurons do not receive electrical excitation. 5. The nicotinic antagonists mecamylamine and d-tubocurarine (both 5 microM) reduced the duration of episodes of fictive swimming recorded from the ventral roots, in spinal embryos. When applied in the middle of a long episode, d-tubocurarine decreased the swimming frequency, ruling out an effect on the initiation pathway. The cholinesterase inhibitor eserine (10 microM) increased the duration of swimming episodes.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
|
|
 |
|
  G. Z. Mentis, F. J. Alvarez, A. Bonnot, D. S. Richards, D. Gonzalez-Forero, R. Zerda, and M. J. O'Donovan Noncholinergic excitatory actions of motoneurons in the neonatal mammalian spinal cord PNAS, May 17, 2005; 102(20): 7344 - 7349. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W.-C. Li, S. R. Soffe, and A. Roberts From The Cover: Glutamate and acetylcholine corelease at developing synapses PNAS, October 26, 2004; 101(43): 15488 - 15493. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Quinlan, P. G. Placas, and J. T. Buchanan Cholinergic Modulation of the Locomotor Network in the Lamprey Spinal Cord J Neurophysiol, September 1, 2004; 92(3): 1536 - 1548. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. D. Lambert, J. Howard, A. Plant, S. Soffe, and A. Roberts Mechanisms and significance of reduced activity and responsiveness in resting frog tadpoles J. Exp. Biol., March 1, 2004; 207(7): 1113 - 1125. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. D. Merrywest, D. L. McLean, J. T. Buchanan, and K. T. Sillar Evolutionary Divergence in Developmental Strategies and Neuromodulatory Control Systems of Two Amphibian Locomotor Networks Integr. Comp. Biol., February 1, 2004; 44(1): 47 - 56. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. G. Hanson and L. T. Landmesser Characterization of the Circuits That Generate Spontaneous Episodes of Activity in the Early Embryonic Mouse Spinal Cord J. Neurosci., January 15, 2003; 23(2): 587 - 600. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Huang, B. R. Noga, P. A. Carr, B. Fedirchuk, and L. M. Jordan Spinal Cholinergic Neurons Activated During Locomotion: Localization and Electrophysiological Characterization J Neurophysiol, June 1, 2000; 83(6): 3537 - 3547. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. W. Ali, R. R. Buss, and P. Drapeau Properties of Miniature Glutamatergic EPSCs in Neurons of the Locomotor Regions of the Developing Zebrafish J Neurophysiol, January 1, 2000; 83(1): 181 - 191. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Buchanan and S. Kasicki Segmental Distribution of Common Synaptic Inputs to Spinal Motoneurons During Fictive Swimming in the Lamprey J Neurophysiol, September 1, 1999; 82(3): 1156 - 1163. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. D. Milner and L. T. Landmesser Cholinergic and GABAergic Inputs Drive Patterned Spontaneous Motoneuron Activity before Target Contact J. Neurosci., April 15, 1999; 19(8): 3007 - 3022. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Staras, G. Kemenes, and P. R. Benjamin Pattern-Generating Role for Motoneurons in a Rhythmically Active Neuronal Network J. Neurosci., May 15, 1998; 18(10): 3669 - 3688. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Green and S. R. Soffe Roles of Ascending Inhibition During Two Rhythmic Motor Patterns in Xenopus Tadpoles J Neurophysiol, May 1, 1998; 79(5): 2316 - 2328. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Chub and M. J. O'Donovan Blockade and Recovery of Spontaneous Rhythmic Activity after Application of Neurotransmitter Antagonists to Spinal Networks of the Chick Embryo J. Neurosci., January 1, 1998; 18(1): 294 - 306. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Perrins and K. R. Weiss A Cerebral Central Pattern Generator in Aplysia and Its Connections with Buccal Feeding Circuitry J. Neurosci., November 1, 1996; 16(21): 7030 - 7045. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
