|
|
||||||||
The Journal of Neurophysiology Vol. 79 No. 4 April 1998,
pp. 1814-1824
Copyright ©1998 The American Physiological Society
Department of Neurology, Yale University School of Medicine, New Haven 06510; and Neuroscience Research Center, Department of Veterans Affairs Medical Center, West Haven, Connecticut 06516
Everill, Brian, Marco A. Rizzo, and Jeffery D. Kocsis. Morphologically identified cutaneous afferent DRG neurons express three different potassium currents in varying proportions. J. Neurophysiol. 79: 1814-1824, 1998. Outward K+ currents were recorded using a whole cell patch-clamp configuration, from acutely dissociated adult rat cutaneous afferent dorsal root ganglion (DRG) neurons (L4 and L5) identified by retrograde labeling with Fluoro-gold. Recordings were obtained 16-24 h after dissociation from cells between 39 and 49 mm in diameter with minimal processes. These cells represent medium-sized DRG neurons relative to the entire population, but are large cutaneous afferent neurons giving rise to myelinated axons. Voltage-activated K+ currents were recorded routinely during 300-ms depolarizing test pulses increasing in 10-mV steps from
40 to +50 mV; the currents were preceded by a 500-ms conditioning prepulse of either
120 or
40 mV. Coexpression of at least three components of K+ current was revealed. Separation of these components was achieved on the basis of sensitivities to the K+ channel blockers, 4-aminopyridine (4-AP) and dendrotoxin (DTx), and by the current responses to variation in conditioning voltage. Changing extracellular K+ concentration from 3 to 40 mM resulted in a shift to the right of the I-V curve commensurate with K+ being the principal charge carrier. Presentation of 100 mM 4-AP revealed a rapidly activating K+ current sensitive to low concentrations of 4-AP. High concentrations of 4-AP (6 mM) extinguished all inactivating current, leaving almost pure sustained current (IK). On the basis of the relative distribution of K+ currents neurons could be separated into three distinct categories: fast inactivating current (IA), slow inactivating current (ID), and sustained current (IK); only IA and IK; and slow inactivating current and IK. However, IK was always the dominant outward current component. These results indicate that considerable variation in K+ currents is present not only in the entire population of DRG neurons, as previously reported, but even within a restricted size and functional group (large cutaneous afferent neurons).
This article has been cited by other articles:
![]() |
J. H. Sun, B. Yang, D. F. Donnelly, C. Ma, and R. H. LaMotte MCP-1 Enhances Excitability of Nociceptive Neurons in Chronically Compressed Dorsal Root Ganglia J Neurophysiol, November 1, 2006; 96(5): 2189 - 2199. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Yoshimura, N. E. Bennett, Y. Hayashi, T. Ogawa, O. Nishizawa, M. B. Chancellor, W. C. de Groat, and S. Seki Bladder overactivity and hyperexcitability of bladder afferent neurons after intrathecal delivery of nerve growth factor in rats. J. Neurosci., October 18, 2006; 26(42): 10847 - 10855. [Abstract] [Full Text] [PDF] |
||||
![]() |
G.-Y. Xu, J. H. Winston, M. Shenoy, H. Yin, and P. J. Pasricha Enhanced excitability and suppression of A-type K+ current of pancreas-specific afferent neurons in a rat model of chronic pancreatitis Am J Physiol Gastrointest Liver Physiol, September 1, 2006; 291(3): G424 - G431. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Yu and J. D. Kocsis Schwann Cell Engraftment Into Injured Peripheral Nerve Prevents Changes in Action Potential Properties J Neurophysiol, August 1, 2005; 94(2): 1519 - 1527. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Yoshida and S. Matsumoto Effects of {alpha}-Dendrotoxin on K+ Currents and Action Potentials in Tetrodotoxin-Resistant Adult Rat Trigeminal Ganglion Neurons J. Pharmacol. Exp. Ther., July 1, 2005; 314(1): 437 - 445. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Vydyanathan, Z.-Z. Wu, S.-R. Chen, and H.-L. Pan A-Type Voltage-Gated K+ Currents Influence Firing Properties of Isolectin B4-Positive But Not Isolectin B4-Negative Primary Sensory Neurons J Neurophysiol, June 1, 2005; 93(6): 3401 - 3409. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Amir, J. D. Kocsis, and M. Devor Multiple Interacting Sites of Ectopic Spike Electrogenesis in Primary Sensory Neurons J. Neurosci., March 9, 2005; 25(10): 2576 - 2585. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Dang, K. Bielefeldt, and G. F. Gebhart Gastric ulcers reduce A-type potassium currents in rat gastric sensory ganglion neurons Am J Physiol Gastrointest Liver Physiol, April 1, 2004; 286(4): G573 - G579. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. K. Boettger, S. Till, M. X. Chen, U. Anand, W. R. Otto, C. Plumpton, D. J. Trezise, S. N. Tate, C. Bountra, K. Coward, et al. Calcium-activated potassium channel SK1- and IK1-like immunoreactivity in injured human sensory neurones and its regulation by neurotrophic factors Brain, February 1, 2002; 125(2): 252 - 263. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Amir, C.-N. Liu, J. D. Kocsis, and M. Devor Oscillatory mechanism in primary sensory neurones Brain, February 1, 2002; 125(2): 421 - 435. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. N. Rasband, E. W. Park, T. W. Vanderah, J. Lai, F. Porreca, and J. S. Trimmer Distinct potassium channels on pain-sensing neurons PNAS, November 6, 2001; 98(23): 13373 - 13378. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Chabbert, J. M. Chambard, A. Sans, and G. Desmadryl Three Types of Depolarization-Activated Potassium Currents in Acutely Isolated Mouse Vestibular Neurons J Neurophysiol, March 1, 2001; 85(3): 1017 - 1026. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. A. Abdulla and P. A. Smith Axotomy- and Autotomy-Induced Changes in Ca2+and K+ Channel Currents of Rat Dorsal Root Ganglion Neurons J Neurophysiol, February 1, 2001; 85(2): 644 - 658. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.-N. Liu, M. Michaelis, R. Amir, and M. Devor Spinal Nerve Injury Enhances Subthreshold Membrane Potential Oscillations in DRG Neurons: Relation to Neuropathic Pain J Neurophysiol, July 1, 2000; 84(1): 205 - 215. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Bordey and H. Sontheimer Differential Inhibition of Glial K+ Currents by 4-AP J Neurophysiol, December 1, 1999; 82(6): 3476 - 3487. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Everill and J. D. Kocsis Reduction in Potassium Currents in Identified Cutaneous Afferent Dorsal Root Ganglion Neurons After Axotomy J Neurophysiol, August 1, 1999; 82(2): 700 - 708. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |