HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 92/2/926    most recent 01025.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Le Ray, D. Articles by Dubuc, R. Search for Related Content PubMed PubMed Citation Articles by Le Ray, D. Articles by Dubuc, R.

Muscarinic Modulation of the Trigemino-Reticular Pathway in Lampreys

¹Département de Kinanthropologie, Université du Québec à Montréal, Montreal, H3C 3P8; and ²Centre de Recherche en Sciences Neurologiques, Université de Montréal, Montreal, Quebec H3C 3J7, Canada

Submitted 23 October 2003; accepted in final form 15 March 2004

In lampreys, reticulospinal neurons integrate sensory inputs to adapt their control onto the spinal locomotor networks. Whether and how sensory inputs to reticulospinal neurons are modulated remains to be determined. We showed recently that cholinergic inputs onto reticulospinal neurons play a key role in the initiation of locomotion elicited by stimulation of the mesencephalic locomotor region in semi intact lampreys. Here, we examined the possible role of muscarinic acetylcholine receptors in modulating trigeminal inputs to reticulospinal neurons. A local application of muscarinic agonists onto an intracellularly recorded reticulospinal cell depressed the disynaptic responses to trigeminal stimulation. A depression was also observed when muscarinic agonists were pressure ejected over the brain stem region containing second-order neurons relaying trigeminal inputs to reticulospinal neurons. Conversely, muscarinic antagonists increased the trigeminal-evoked responses, suggesting that a muscarinic depression of sensory inputs to RS neurons is exerted tonically. The muscarinic modulation affected predominantly the N-methyl-D-aspartate (NMDA) component of the trigeminal-evoked responses. Moreover, atropine perfusion facilitated the occurrence of sustained depolarizations induced by stimulation of the trigeminal nerve, and it revealed NMDA-induced intrinsic oscillations in reticulospinal neurons. The functional significance of a muscarinic modulation of a sensory transmission to reticulospinal neurons is discussed.

This article has been cited by other articles:

				K. A. Quinlan and J. T. Buchanan Cellular and Synaptic Actions of Acetylcholine in the Lamprey Spinal Cord J Neurophysiol, August 1, 2008; 100(2): 1020 - 1031. [Abstract] [Full Text] [PDF]

				A. W. Jackson, F. A. Pino, E. D. Wiebe, and A. D. McClellan Movements and Muscle Activity Initiated by Brain Locomotor Areas in Semi-Intact Preparations From Larval Lamprey J Neurophysiol, May 1, 2007; 97(5): 3229 - 3241. [Abstract] [Full Text] [PDF]

				R. W. Smetana, S. Alford, and R. Dubuc Muscarinic Receptor Activation Elicits Sustained, Recurring Depolarizations in Reticulospinal Neurons J Neurophysiol, May 1, 2007; 97(5): 3181 - 3192. [Abstract] [Full Text] [PDF]

				G. B. Miles, R. Hartley, A. J. Todd, and R. M. Brownstone Spinal cholinergic interneurons regulate the excitability of motoneurons during locomotion PNAS, February 13, 2007; 104(7): 2448 - 2453. [Abstract] [Full Text] [PDF]

				S. Rossignol, R. Dubuc, and J.-P. Gossard Dynamic Sensorimotor Interactions in Locomotion Physiol Rev, January 1, 2006; 86(1): 89 - 154. [Abstract] [Full Text] [PDF]