| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Neurophysiol (January 1, 2003). 10.1152/jn.00241.2002
Submitted on Submitted 3 April 2002; accepted in final form 26 August 2002
Department of Physiology and Biophysics, University of Washington, School of Medicine, Seattle, Washington 98195
Powers, Randall K. and
Marc D. Binder.
Persistent Sodium and Calcium Currents in Rat Hypoglossal
Motoneurons. J. Neurophysiol. 89: 615-624, 2003. Voltage-dependent persistent inward currents are thought to
make an important contribution to the input-output properties of
motoneurons, influencing both the transfer of synaptic current to
the soma and the effects of that current on repetitive discharge. Recent studies have paid particular attention to the contribution of
L-type calcium channels, which are thought to be widely distributed on
both the somatic and the dendritic membrane. However, the relative contribution of different channel subtypes as well as their
somatodendritic distribution may vary among motoneurons of different
species, developmental stages, and motoneuron pools. In this study, we have characterized persistent inward currents in juvenile (10- to
24-day-old) rat hypoglossal (HG) motoneurons. Whole-cell, voltage-clamp recordings were made from the somata of visualized rat HG motoneurons in 300-µm brain stem slices. Slow (10 s), triangular voltage-clamp commands from a holding potential of 70 to 0 mV and back elicited whole-cell currents that were dominated by outward, potassium currents,
but often showed a region of negative slope resistance on the rising
phase of the command. In the presence of potassium channel blockers
(internal cesium and external 4-aminopyridine and tetraethylammonium),
net inward currents were present on both the rising and falling phases
of the voltage-clamp command. A portion of the inward current present
on the ascending phase of the command was mediated by TTX-sensitive
sodium channels, whereas calcium channels mediated the remainder of the
current. We found roughly the same relative contributions of P-, N-,
and L-type channels to the calcium currents recorded at the soma that
had previously been found in neonatal rat HG motoneurons. In most cells, the somatic voltage thresholds for calcium current onset and
offset were similar and the peak current was largest on the ascending
phase of the clamp command. However, about one-third of the cells
exhibited a substantial clockwise current hysteresis, i.e., inward
currents were present at lower voltages on the descending phase of the
clamp command. In the same cells, 1-s depolarizing voltage-clamp
commands were followed by prolonged tail currents, consistent with a
prominent contribution from dendritic channels. In contrast to previous
reports on turtle and mouse motoneurons, blocking L-type calcium
channels did not eliminate these presumed dendritic currents.
This article has been cited by other articles:
|
|
 |
|
  C.J. Heckman, M. Johnson, C. Mottram, and J. Schuster Persistent Inward Currents in Spinal Motoneurons and Their Influence on Human Motoneuron Firing Patterns Neuroscientist, June 1, 2008; 14(3): 264 - 275. [Abstract] [PDF]
|
|
|
|
 |
|
 H. Koizumi, C. G. Wilson, S. Wong, T. Yamanishi, N. Koshiya, and J. C. Smith Functional Imaging, Spatial Reconstruction, and Biophysical Analysis of a Respiratory Motor Circuit Isolated In Vitro J. Neurosci., March 5, 2008; 28(10): 2353 - 2365. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. V. Bui, G. Grande, and P. K. Rose Relative Location of Inhibitory Synapses and Persistent Inward Currents Determines the Magnitude and Mode of Synaptic Amplification in Motoneurons J Neurophysiol, February 1, 2008; 99(2): 583 - 594. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manuel, C. Meunier, M. Donnet, and D. Zytnicki Resonant or Not, Two Amplification Modes of Proprioceptive Inputs by Persistent Inward Currents in Spinal Motoneurons J. Neurosci., November 21, 2007; 27(47): 12977 - 12988. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Diaz-Rios, D. A. Dombeck, W. W. Webb, and R. M. Harris-Warrick Serotonin Modulates Dendritic Calcium Influx in Commissural Interneurons in the Mouse Spinal Locomotor Network J Neurophysiol, October 1, 2007; 98(4): 2157 - 2167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Brownstone Take Your PIC: Motoneuronal Persistent Inward Currents May Be Somatic as Well as Dendritic. Focus on "Facilitation of Somatic Calcium Channels Can Evoke Prolonged Tail Currents in Rat Hypoglossal Motoneurons" J Neurophysiol, August 1, 2007; 98(2): 579 - 580. [Full Text] [PDF]
|
|
|
|
|
|
A. T. Moritz, G. Newkirk, R. K. Powers, and M. D. Binder Facilitation of Somatic Calcium Channels Can Evoke Prolonged Tail Currents in Rat Hypoglossal Motoneurons J Neurophysiol, August 1, 2007; 98(2): 1042 - 1047. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. P. Shapiro and R. H. Lee Synaptic Amplification Versus Bistability in Motoneuron Dendritic Processing: A Top-Down Modeling Approach J Neurophysiol, June 1, 2007; 97(6): 3948 - 3960. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Margolis and P. B. Detwiler Different Mechanisms Generate Maintained Activity in ON and OFF Retinal Ganglion Cells J. Neurosci., May 30, 2007; 27(22): 5994 - 6005. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Li and D. J. Bennett Apamin-Sensitive Calcium-Activated Potassium Currents (SK) Are Activated by Persistent Calcium Currents in Rat Motoneurons J Neurophysiol, May 1, 2007; 97(5): 3314 - 3330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. P. Cramer, Y. Li, and A. Keller The Whisking Rhythm Generator: A Novel Mammalian Network for the Generation of Movement J Neurophysiol, March 1, 2007; 97(3): 2148 - 2158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Harvey, Y. Li, X. Li, and D. J. Bennett Persistent Sodium Currents and Repetitive Firing in Motoneurons of the Sacrocaudal Spinal Cord of Adult Rats J Neurophysiol, September 1, 2006; 96(3): 1141 - 1157. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. J. Kuo, R. H. Lee, L. Zhang, and C. J. Heckman Essential role of the persistent sodium current in spike initiation during slowly rising inputs in mouse spinal neurones J. Physiol., August 1, 2006; 574(3): 819 - 834. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Le, D. R. Verley, J.-M. Goaillard, D. I. Messinger, A. E. Christie, and J. T. Birmingham Bistable Behavior Originating in the Axon of a Crustacean Motor Neuron J Neurophysiol, March 1, 2006; 95(3): 1356 - 1368. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. V. Bui, M. Ter-Mikaelian, D. Bedrossian, and P. K. Rose Computational Estimation of the Distribution of L-type Ca2+ Channels in Motoneurons Based on Variable Threshold of Activation of Persistent Inward Currents J Neurophysiol, January 1, 2006; 95(1): 225 - 241. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. ElBasiouny, D. J. Bennett, and V. K. Mushahwar Simulation of Dendritic CaV1.3 Channels in Cat Lumbar Motoneurons: Spatial Distribution J Neurophysiol, December 1, 2005; 94(6): 3961 - 3974. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Wu, A. Enomoto, S. Tanaka, C.-F. Hsiao, D. Q. Nykamp, E. Izhikevich, and S. H. Chandler Persistent Sodium Currents in Mesencephalic V Neurons Participate in Burst Generation and Control of Membrane Excitability J Neurophysiol, May 1, 2005; 93(5): 2710 - 2722. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. K. Purvis and R. J. Butera Ionic Current Model of a Hypoglossal Motoneuron J Neurophysiol, February 1, 2005; 93(2): 723 - 733. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Zeng, R. K. Powers, G. Newkirk, M. Yonkers, and M. D. Binder Contribution of Persistent Sodium Currents to Spike-Frequency Adaptation in Rat Hypoglossal Motoneurons J Neurophysiol, February 1, 2005; 93(2): 1035 - 1041. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. G. Maltenfort and T. M. Hamm Estimation of the Electrical Parameters of Spinal Motoneurons Using Impedance Measurements J Neurophysiol, September 1, 2004; 92(3): 1433 - 1444. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Bergmann and B. U. Keller Impact of mitochondrial inhibition on excitability and cytosolic Ca2+ levels in brainstem motoneurones from mouse J. Physiol., February 15, 2004; 555(1): 45 - 59. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. I. Kononenko, L.-R. Shao, and F. E. Dudek Riluzole-Sensitive Slowly Inactivating Sodium Current in Rat Suprachiasmatic Nucleus Neurons J Neurophysiol, February 1, 2004; 91(2): 710 - 718. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Taylor and R. M. Enoka Quantification of the Factors That Influence Discharge Correlation in Model Motor Neurons J Neurophysiol, February 1, 2004; 91(2): 796 - 814. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. V. Bui, S. Cushing, D. Dewey, R. E. Fyffe, and P. K. Rose Comparison of the Morphological and Electrotonic Properties of Renshaw Cells, Ia Inhibitory Interneurons, and Motoneurons in the Cat J Neurophysiol, November 1, 2003; 90(5): 2900 - 2918. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Li and D. J. Bennett Persistent Sodium and Calcium Currents Cause Plateau Potentials in Motoneurons of Chronic Spinal Rats J Neurophysiol, August 1, 2003; 90(2): 857 - 869. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Pfeuty, G. Mato, D. Golomb, and D. Hansel Electrical Synapses and Synchrony: The Role of Intrinsic Currents J. Neurosci., July 16, 2003; 23(15): 6280 - 6294. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
