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: 93/6/3401    most recent 01267.2004v2 01267.2004v1 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 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 Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Vydyanathan, A. Articles by Pan, H.-L. Search for Related Content PubMed PubMed Citation Articles by Vydyanathan, A. Articles by Pan, H.-L.

A-Type Voltage-Gated K⁺ Currents Influence Firing Properties of Isolectin B₄-Positive But Not Isolectin B₄-Negative Primary Sensory Neurons

Department of Anesthesiology, Pennsylvania State University College of Medicine, The Milton S. Hershey Medical Center, Hershey, Pennsylvania

Submitted 9 December 2004; accepted in final form 6 January 2005

Voltage-gated K⁺ channels (Kv) in primary sensory neurons are important for regulation of neuronal excitability. The dorsal root ganglion (DRG) neurons are heterogeneous, and the types of native Kv currents in different groups of nociceptive DRG neurons are not fully known. In this study, we determined the difference in the A-type Kv current and its influence on the firing properties between isolectin B₄ (IB₄)-positive and -negative DRG neurons. Whole cell voltage- and current-clamp recordings were performed on acutely dissociated small DRG neurons of rats. The total Kv current density was significantly higher in IB₄-positive than that in IB₄-negative neurons. Also, 4-aminopyridine (4-AP) produced a significantly greater reduction in Kv currents in IB₄-positive than in IB₄-negative neurons. In contrast, IB₄-negative neurons exhibited a larger proportion of tetraethylammonium-sensitive Kv currents. Furthermore, IB₄-positive neurons showed a longer latency of firing and required a significantly larger amount of current injection to evoke action potentials. 4-AP significantly decreased the latency of firing and increased the firing frequency in IB₄-positive but not in IB₄-negative neurons. Additionally, IB₄-positive neurons are immunoreactive to Kv1.4 but not to Kv1.1 and Kv1.2 subunits. Collectively, this study provides new information that 4-AP–sensitive A-type Kv currents are mainly present in IB₄-positive DRG neurons and preferentially dampen the initiation of action potentials of this subpopulation of nociceptors. The difference in the density of A-type Kv currents contributes to the distinct electrophysiological properties of IB₄-positive and -negative DRG neurons.

This article has been cited by other articles:

				E. Bocksteins, A. L. Raes, G. Van de Vijver, T. Bruyns, P.-P. Van Bogaert, and D. J. Snyders Kv2.1 and silent Kv subunits underlie the delayed rectifier K+ current in cultured small mouse DRG neurons Am J Physiol Cell Physiol, June 1, 2009; 296(6): C1271 - C1278. [Abstract] [Full Text] [PDF]

				L. Catacuzzeno, B. Fioretti, D. Pietrobon, and F. Franciolini The differential expression of low-threshold K+ currents generates distinct firing patterns in different subtypes of adult mouse trigeminal ganglion neurones J. Physiol., November 1, 2008; 586(21): 5101 - 5118. [Abstract] [Full Text] [PDF]

				B. A. Graham, A. M. Brichta, and R. J. Callister Recording Temperature Affects the Excitability of Mouse Superficial Dorsal Horn Neurons, In Vitro J Neurophysiol, May 1, 2008; 99(5): 2048 - 2059. [Abstract] [Full Text] [PDF]

				H.-J. Hu, B. J. Alter, Y. Carrasquillo, C.-S. Qiu, and R. W. Gereau IV Metabotropic Glutamate Receptor 5 Modulates Nociceptive Plasticity via Extracellular Signal-Regulated Kinase Kv4.2 Signaling in Spinal Cord Dorsal Horn Neurons J. Neurosci., November 28, 2007; 27(48): 13181 - 13191. [Abstract] [Full Text] [PDF]

				L.-Y. Chien, J.-K. Cheng, D. Chu, C.-F. Cheng, and M.-L. Tsaur Reduced Expression of A-Type Potassium Channels in Primary Sensory Neurons Induces Mechanical Hypersensitivity J. Neurosci., September 12, 2007; 27(37): 9855 - 9865. [Abstract] [Full Text] [PDF]

				Z.-Z. Wu and H.-L. Pan Role of TRPV1 and intracellular Ca2+ in excitation of cardiac sensory neurons by bradykinin Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R276 - R283. [Abstract] [Full Text] [PDF]

				Q. Chen and H.-L. Pan Signaling Mechanisms of Angiotensin II-Induced Attenuation of GABAergic Input to Hypothalamic Presympathetic Neurons J Neurophysiol, May 1, 2007; 97(5): 3279 - 3287. [Abstract] [Full Text] [PDF]

				J.-S. Choi, S. D. Dib-Hajj, and S. G. Waxman Differential Slow Inactivation and Use-Dependent Inhibition of Nav1.8 Channels Contribute to Distinct Firing Properties in IB4+ and IB4- DRG Neurons J Neurophysiol, February 1, 2007; 97(2): 1258 - 1265. [Abstract] [Full Text] [PDF]

				J.-H. Zheng, E. T. Walters, and X.-J. Song Dissociation of Dorsal Root Ganglion Neurons Induces Hyperexcitability That Is Maintained by Increased Responsiveness to cAMP and cGMP J Neurophysiol, January 1, 2007; 97(1): 15 - 25. [Abstract] [Full Text] [PDF]

				X. Fang, L. Djouhri, S. McMullan, C. Berry, S. G. Waxman, K. Okuse, and S. N. Lawson Intense isolectin-B4 binding in rat dorsal root ganglion neurons distinguishes C-fiber nociceptors with broad action potentials and high Nav1.9 expression. J. Neurosci., July 5, 2006; 26(27): 7281 - 7292. [Abstract] [Full Text] [PDF]

				T. F. Finnegan, S.-R. Chen, and H.-L. Pan {micro} Opioid Receptor Activation Inhibits GABAergic Inputs to Basolateral Amygdala Neurons Through Kv1.1/1.2 Channels J Neurophysiol, April 1, 2006; 95(4): 2032 - 2041. [Abstract] [Full Text] [PDF]