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: 96/3/1227    most recent 01170.2005v1 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 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 (2) Citing Articles via Google Scholar Google Scholar Articles by Butovas, S. Articles by Schwarz, C. Search for Related Content PubMed PubMed Citation Articles by Butovas, S. Articles by Schwarz, C.

Effects of Electrically Coupled Inhibitory Networks on Local Neuronal Responses to Intracortical Microstimulation

¹Hertie-Institute for Clinical Brain Research, Department of Cognitive Neurology, University Tübingen, Tübingen; and ²Department of Clinical Neurobiology, University Hospital of Neurology, Heidelberg, Germany

Submitted 4 November 2005; accepted in final form 15 May 2006

Using in vivo multielectrode electrophysiology in mice, we investigated the underpinnings of a local, long-lasting firing rate suppression evoked by intracortical microstimulation. Synaptic inhibition contributes to this suppression as it was reduced by pharmacological blockade of -aminobutyric acid type B (GABA_B) receptors. Blockade of GABA_B receptors also abolished the known sublinear addition of inhibitory response duration after repetitive electrical stimulation. Furthermore, evoked inhibition was weaker and longer in connexin 36 knockout (KO) mice that feature decoupled cortical inhibitory networks. In supragranular layers of KO mice even an unusually long excitatory response (50 ms) appeared that was never observed in wild-type (WT) mice. Furthermore, the spread and duration of very fast oscillations (>200 Hz) evoked by microstimulation at a short latency were strongly enhanced in KO mice. In the spatial domain, lack of connexin 36 unmasked a strong anisotropy of inhibitory spread. Although its reach along layers was almost the same as that in WT mice, the spread across cortical depth was severely hampered. In summary, the present data suggest that connexin 36–coupled networks significantly shape the electrically evoked cortical inhibitory response. Electrical coupling renders evoked cortical inhibition more precise and strong and ensures a uniform spread along the two cardinal axes of neocortical geometry.

This article has been cited by other articles:

				D. L. Kimmel and T. Moore Temporal Patterning of Saccadic Eye Movement Signals J. Neurosci., July 18, 2007; 27(29): 7619 - 7630. [Abstract] [Full Text] [PDF]