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: 93/5/2966    most recent 00556.2004v1 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 ISI 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 ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Wiest, M. C. Articles by Nicolelis, M. A. L. Search for Related Content PubMed PubMed Citation Articles by Wiest, M. C. Articles by Nicolelis, M. A. L.

INNOVATIVE METHODOLOGY

Heterogeneous Integration of Bilateral Whisker Signals by Neurons in Primary Somatosensory Cortex of Awake Rats

¹Departments of Neurobiology, ²Biomedical Engineering, and ³Psychological and Brain Sciences, and ⁴Duke University Center for Neuroengineering, Duke Medical Center, Durham, North Carolina; and ⁵Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina

Submitted 27 May 2004; accepted in final form 17 November 2004

Bilateral single-unit recordings in primary somatosensory cortex (S1) of anesthetized rats have revealed substantial cross talk between cortical hemispheres, suggesting the possibility that behaviorally relevant bilateral integration could occur in S1. To determine the extent of bilateral neural responses in awake animals, we recorded S1 multi- and single-unit activity in head-immobilized rats while stimulating groups of 4 whiskers from the same column on both sides of the head. Results from these experiments confirm the widespread presence of single units responding to tactile stimuli on either side of the face in S1 of awake animals. Quantification of bilateral integration by multiunits revealed both facilitative and suppressive integration of bilateral inputs. Varying the interval between left and right whisker stimuli between 0 and 120 ms showed the temporal integration of bilateral stimuli to be dominated on average by suppression at intervals around 30 ms, in agreement with comparable recordings in anesthetized animals. Contrary to the anesthetized data, in the awake animals we observed a high level of heterogeneity of bilateral responses and a strong interaction between synchronous bilateral stimuli. The results challenge the traditional conception of highly segregated hemispheric processing channels in the rat S1 cortex, and support the hypothesis that callosal cross-projections between the two hemispheres mediate rats' known ability to integrate bilateral whisker signals.

This article has been cited by other articles:

				J. Pantoja, S. Ribeiro, M. Wiest, E. Soares, D. Gervasoni, N. A. M. Lemos, and M. A. L. Nicolelis Neuronal Activity in the Primary Somatosensory Thalamocortical Loop Is Modulated by Reward Contingency during Tactile Discrimination J. Neurosci., September 26, 2007; 27(39): 10608 - 10620. [Abstract] [Full Text] [PDF]

				M. H.P. Kole, A. U. Brauer, and G. J. Stuart Inherited cortical HCN1 channel loss amplifies dendritic calcium electrogenesis and burst firing in a rat absence epilepsy model J. Physiol., January 15, 2007; 578(2): 507 - 525. [Abstract] [Full Text] [PDF]

				R. Gutierrez, J. M. Carmena, M. A. L. Nicolelis, and S. A. Simon Orbitofrontal Ensemble Activity Monitors Licking and Distinguishes Among Natural Rewards J Neurophysiol, January 1, 2006; 95(1): 119 - 133. [Abstract] [Full Text] [PDF]

				L. Li, V. Rema, and F. F. Ebner Chronic Suppression of Activity in Barrel Field Cortex Downregulates Sensory Responses in Contralateral Barrel Field Cortex J Neurophysiol, November 1, 2005; 94(5): 3342 - 3356. [Abstract] [Full Text] [PDF]