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: 578/1/173    most recent jphysiol.2006.119016v1 Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Castro-Alamancos, M. A. Articles by Tawara-Hirata, Y. Search for Related Content PubMed PubMed Citation Articles by Castro-Alamancos, M. A. Articles by Tawara-Hirata, Y. Related Collections Neuroscience

¹ Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA

The motor cortex generates synchronous network oscillations at frequencies between 7 and 14 Hz during disinhibition or low [Mg²⁺]_o buffers, but the underlying mechanisms are poorly understood. These oscillations, termed here 10 Hz oscillations, are generated by a purely excitatory network of interconnected pyramidal cells because they are robust in the absence of GABAergic transmission. It is likely that specific voltage-dependent currents expressed in those cells contribute to the generation of 10 Hz oscillations. We tested the effects of different drugs known to suppress certain voltage-dependent currents. The results revealed that drugs that suppress the low-threshold calcium current and the hyperpolarization-activated cation current are not critically involved in the generation of 10 Hz oscillations. Interestingly, drugs known to suppress the persistent sodium current abolished 10 Hz oscillations. Furthermore, blockers of K⁺ channels had significant effects on the oscillations. In particular, blockers of the M-current abolished the oscillations. Also, blockers of both non-inactivating and slowly inactivating voltage-dependent K⁺ currents abolished 10 Hz oscillations. The results indicate that specific voltage-dependent non-inactivating K⁺ currents, such as the M-current, and persistent sodium currents are critically involved in generating 10 Hz oscillations of excitatory motor cortex networks.

(Received 10 August 2006; accepted after revision 30 August 2006; first published online 31 August 2006)
Corresponding author M. Castro-Alamancos: Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA. Email: manuel.castro{at}drexel.edu

This article has been cited by other articles:

				R. L. Ramos and V. Khatri Motor cortical network oscillations driven by voltage- and ligand-gated currents J. Physiol., May 1, 2007; 580(3): 701 - 702. [Full Text] [PDF]

				M. A. Castro-Alamancos What Generates Whisking? Focus on: "The Whisking Rhythm Generator: A Novel Mammalian Network for the Generation of Movement" J Neurophysiol, March 1, 2007; 97(3): 1883 - 1884. [Full Text] [PDF]