 |
|||||
|
|||||
|
|||||
|
|||||
|
|||||
Previous Article | Next Article
The Journal of Neuroscience, March 1, 2003, 23(5):1924
Reversible Disorganization of the Locomotor Pattern after Neonatal Spinal Cord Transection in the Rat
Jean-Chrétien Norreel*, Jean-François Pflieger*, Edouard Pearlstein, Juliette Simeoni-Alias, François Clarac, and Laurent Vinay Développement et Pathologie du Mouvement, Centre National de la Recherche Scientifique, F-13402 Marseille Cedex 20, France
The central pattern generators (CPGs) for locomotion, located in the lumbar spinal cord, are functional at birth in the rat. Their maturation occurs during the last few days preceding birth, a period during which the first projections from the brainstem start to reach the lumbar enlargement of the spinal cord. The goal of the present study was to investigate the effect of suppressing inputs from supraspinal structures on the CPGs, shortly after their formation. The spinal cord was transected at the thoracic level at birth [postnatal day 0 (P0)]. We examined during the first postnatal week the capacity of the CPGs to produce rhythmic motor activity in two complementary experimental conditions. Left and right ankle extensor muscles were recorded in vivo during airstepping, and lumbar ventral roots were recorded in vitro during pharmacologically evoked fictive locomotion. Mechanical stimulation of the tail elicited long-lasting sequences of airstepping in the spinal neonates and only a few steps in sham-operated rats. In vitro experiments made simultaneously on spinal and sham animals confirmed the increased excitability of the CPGs after spinalization. A left-right alternating locomotor pattern was observed at P1-P3. Both types of experiments showed that the pattern was disorganized at P6-P7, and that the left-right alternation was lost. Alternation was restored after the activation of serotonergic 5-HT2 receptors in vivo. These results suggest that descending pathways, in particular serotonergic projections, control the strength of reciprocal inhibition and therefore shape the locomotor pattern in the neonatal rat.
Key words: central pattern generators; locomotion; development; descending pathways; serotonin; spinal cord transection
* J.-C.N. and J.-F.P contributed equally to this work.
Copyright © 2003 Society for Neuroscience 0270-6474/03/2351924-09$05.00/0
This article has been cited by other articles:
B. R. Noga, D. M. G. Johnson, M. I. Riesgo, and A. Pinzon
Locomotor-Activated Neurons of the Cat. I. Serotonergic Innervation and Co-Localization of 5-HT7, 5-HT2A, and 5-HT1A Receptors in the Thoraco-Lumbar Spinal Cord
J Neurophysiol, September 1, 2009; 102(3): 1560 - 1576.
[Abstract] [Full Text] [PDF]
N. P. Lapointe and P. A. Guertin
Synergistic Effects of D1/5 and 5-HT1A/7 Receptor Agonists on Locomotor Movement Induction in Complete Spinal Cord-Transected Mice
J Neurophysiol, July 1, 2008; 100(1): 160 - 168.
[Abstract] [Full Text] [PDF]
I. T. Gordon and P. J. Whelan
Brainstem modulation of locomotion in the neonatal mouse spinal cord
J. Physiol., May 15, 2008; 586(10): 2487 - 2497.
[Abstract] [Full Text] [PDF]
N. P. Lapointe, R.-V. Ung, and P. A. Guertin
Plasticity in Sublesionally Located Neurons Following Spinal Cord Injury
J Neurophysiol, November 1, 2007; 98(5): 2497 - 2500.
[Abstract] [Full Text] [PDF]
S. Tazerart, J.-C. Viemari, P. Darbon, L. Vinay, and F. Brocard
Contribution of Persistent Sodium Current to Locomotor Pattern Generation in Neonatal Rats
J Neurophysiol, August 1, 2007; 98(2): 613 - 628.
[Abstract] [Full Text] [PDF]
J. C. Petruska, R. M. Ichiyama, D. L. Jindrich, E. D. Crown, K. E. Tansey, R. R. Roy, V. R. Edgerton, and L. M. Mendell
Changes in Motoneuron Properties and Synaptic Inputs Related to Step Training after Spinal Cord Transection in Rats
J. Neurosci., April 18, 2007; 27(16): 4460 - 4471.
[Abstract] [Full Text] [PDF]
I. T. Gordon and P. J. Whelan
Monoaminergic Control of Cauda-Equina-Evoked Locomotion in the Neonatal Mouse Spinal Cord
J Neurophysiol, December 1, 2006; 96(6): 3122 - 3129.
[Abstract] [Full Text] [PDF]
C. Jean-Xavier, J.-F. Pflieger, S. Liabeuf, and L. Vinay
Inhibitory Postsynaptic Potentials in Lumbar Motoneurons Remain Depolarizing After Neonatal Spinal Cord Transection in the Rat
J Neurophysiol, November 1, 2006; 96(5): 2274 - 2281.
[Abstract] [Full Text] [PDF]
A.-E. Allain, P. Meyrand, and P. Branchereau
Ontogenic Changes of the Spinal GABAergic Cell Population Are Controlled by the Serotonin (5-HT) System: Implication of 5-HT1 Receptor Family
J. Neurosci., September 21, 2005; 25(38): 8714 - 8724.
[Abstract] [Full Text] [PDF]
M. J O'Donovan
Serotonergic neurones drive spontaneous activity in the developing mouse hindbrain
J. Physiol., August 1, 2005; 566(3): 643 - 643.
[Full Text] [PDF]
M. A. Madriaga, L. C. McPhee, T. Chersa, K. J. Christie, and P. J. Whelan
Modulation of Locomotor Activity by Multiple 5-HT and Dopaminergic Receptor Subtypes in the Neonatal Mouse Spinal Cord
J Neurophysiol, September 1, 2004; 92(3): 1566 - 1576.
[Abstract] [Full Text] [PDF]
D. L McLean and K. T Sillar
Spinal and supraspinal functions of noradrenaline in the frog embryo: consequences for motor behaviour
J. Physiol., September 1, 2003; 551(2): 575 - 587.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|