J Physiol Society Meetings
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Physiology in Press

First published online on March 15, 2002.
 Copyright © 2002 by The Physiological Society
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
540/3/875    most recent
2001.015982v1
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Alaburda, A.
Right arrow Articles by Hounsgaard, J.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Alaburda, A.
Right arrow Articles by Hounsgaard, J.

Received December 20, 2001
Accepted after revision March 11, 2002

An M-like outward current regulates the excitability of spinal motoneurons in the adult turtle

Aidas Alaburda1, Jean-Francois Perrier1, and Jørn Hounsgaard2*

1 Department of Medical Physiology, Panum Institute, University of Copenhagen, Copenhagen N. DK 2200, Denmark
2 Department of Medical Physiology, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen N. DK-2200, Denmark

* To whom correspondence should be addressed. E-mail: j.hounsgaard{at}mfi.ku.dk.

The excitatory action of muscarine on spinal motoneurones was investigated with intracellular recordings in a slice preparation from adult turtles. In these cells muscarine is known to facilitate a persistent inward current mediated by L-type Ca2+ channels. When this effect was blocked by nifedipine, muscarine still increased the excitability. In voltage clamp, a slowly activating outward current, generated during depolarizing voltage commands and deactivating as a tail current on return to the holding voltage, was reduced by muscarine. This outward current was activated when the voltage was stepped to potentials positive to -60 mV, was voltage sensitive and had a deactivation time constant of ~80 ms. These findings are compatible with an M-current. This possibility was also supported by the finding that the current was reduced by XE-991 - a selective blocker of the KCNQ potassium channels underlying M-currents in other cell types. Our findings suggest that an M-like current, mediated by a KCNQ channel, contributes to the intrinsic response properties of motoneurones in the adult spinal cord by increasing adaptation of repetitive firing and decreasing the slope of the frequency-current relation.




This article has been cited by other articles:


Home page
 J. Neurosci.Home page
S. A. Prescott and T. J. Sejnowski
Spike-Rate Coding and Spike-Time Coding Are Affected Oppositely by Different Adaptation Mechanisms
J. Neurosci., December 10, 2008; 28(50): 13649 - 13661.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
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]

Home page
 J. Physiol.Home page
J.-F. Perrier and F. Cotel
Serotonin differentially modulates the intrinsic properties of spinal motoneurons from the adult turtle
J. Physiol., March 1, 2008; 586(5): 1233 - 1238.
[Abstract] [Full Text] [PDF]

Home page
 J Biomol ScreenHome page
F. Jow, Ru Shen, P. Chanda, E. Tseng, H. Zhang, J. Kennedy, J. Dunlop, and M. R. Bowlby
Validation of a Medium-Throughput Electrophysiological Assay for KCNQ2/3 Channel Enhancers Using IonWorks HT
J Biomol Screen, December 1, 2007; 12(8): 1059 - 1067.
[Abstract] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
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]

Home page
 J. Neurophysiol.Home page
M. Smith and J.-F. Perrier
Intrinsic Properties Shape the Firing Pattern of Ventral Horn Interneurons From the Spinal Cord of the Adult Turtle
J Neurophysiol, November 1, 2006; 96(5): 2670 - 2677.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
S. Chevallier, F. Nagy, and J.-M. Cabelguen
Cholinergic control of excitability of spinal motoneurones in the salamander
J. Physiol., February 1, 2006; 570(3): 525 - 540.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
G. B Miles, Y Dai, and R. M Brownstone
Mechanisms underlying the early phase of spike frequency adaptation in mouse spinal motoneurones
J. Physiol., July 15, 2005; 566(2): 519 - 532.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
M. Van Cutsem and J. Duchateau
Preceding muscle activity influences motor unit discharge and rate of torque development during ballistic contractions in humans
J. Physiol., January 15, 2005; 562(2): 635 - 644.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
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]

Home page
 J. Physiol.Home page
E. A. L. Muennich and R. E. W. Fyffe
Focal aggregation of voltage-gated, Kv2.1 subunit-containing, potassium channels at synaptic sites in rat spinal motoneurones
J. Physiol., February 1, 2004; 554(3): 673 - 685.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2002 The Physiological Society.