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) 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 (6) Citing Articles via Google Scholar Google Scholar Articles by Cissé, Y. Articles by Steriade, M. Search for Related Content PubMed PubMed Citation Articles by Cissé, Y. Articles by Steriade, M.

Synaptic Enhancement Induced Through Callosal Pathways in Cat Association Cortex

Laboratoire de Neurophysiologie, Faculté de Médecine, Université Laval, Quebec G1K 7P4, Canada

Submitted 20 May 2004; accepted in final form 21 July 2004

The corpus callosum plays a major role in synchronizing neocortical activities in the two hemispheres. We investigated the changes in callosally elicited excitatory postsynaptic potentials (EPSPs) of neurons from cortical association areas 5 and 7 of cats under barbiturate or ketamine-xylazine anesthesia. Single pulses to callosal pathway evoked control EPSPs; pulse-trains were subsequently applied at different frequencies to homotopic sites in the contralateral cortex, as conditioning stimulation; thereafter, the single pulses were applied again to test changes in synaptic responsiveness by comparing the amplitudes of control and conditioned EPSPs. In 41 of 42 neurons recorded under barbiturate anesthesia, all frequencies of conditioning callosal stimuli induced short-term (5–30 min) enhancement of test EPSPs elicited by single stimuli. Neurons tested with successive conditioning pulse-trains at different frequencies displayed stronger enhancement with high-frequency (40–100 Hz) than with low-frequency (10–20 Hz) rhythmic pulse-trains; >100 Hz, the potentiation saturated. In a neuronal sample, microdialysis of an N-methyl-D-aspartate (NMDA) receptor blocker in barbiturate-treated cats suppressed this potentiation, and potentiation of callosally evoked EPSPs was not detected in neurons recorded under ketamine-xylazine anesthesia, thus indicating that EPSPs' potentiation implicates, at least partially, NMDA receptors. These data suggest that callosal activities occurring within low-frequency and fast-frequency oscillations play a role in cortical synaptic plasticity.

This article has been cited by other articles:

				T. Karayannis, I. Huerta-Ocampo, and M. Capogna GABAergic and Pyramidal Neurons of Deep Cortical Layers Directly Receive and Differently Integrate Callosal Input Cereb Cortex, May 1, 2007; 17(5): 1213 - 1226. [Abstract] [Full Text] [PDF]

				M. G. Knyazeva, E. Fornari, R. Meuli, and P. Maeder Interhemispheric Integration at Different Spatial Scales: The Evidence From EEG Coherence and fMRI J Neurophysiol, July 1, 2006; 96(1): 259 - 275. [Abstract] [Full Text] [PDF]

				S. Crochet, P. Fuentealba, Y. Cisse, I. Timofeev, and M. Steriade Synaptic Plasticity in Local Cortical Network In Vivo and Its Modulation by the Level of Neuronal Activity Cereb Cortex, May 1, 2006; 16(5): 618 - 631. [Abstract] [Full Text] [PDF]