<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bal, T</style></author><author><style face="normal" font="default" size="100%">Debay, D</style></author><author><style face="normal" font="default" size="100%">Destexhe, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cortical feedback controls the frequency and synchrony of oscillations in the visual thalamus.</style></title><secondary-title><style face="normal" font="default" size="100%">J Neurosci</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Neurosci.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Action Potentials</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Axons</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological Clocks</style></keyword><keyword><style  face="normal" font="default" size="100%">Cerebral Cortex</style></keyword><keyword><style  face="normal" font="default" size="100%">Computer Simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Electric Stimulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Excitatory Postsynaptic Potentials</style></keyword><keyword><style  face="normal" font="default" size="100%">Feedback</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferrets</style></keyword><keyword><style  face="normal" font="default" size="100%">GABA Antagonists</style></keyword><keyword><style  face="normal" font="default" size="100%">GABA-B Receptor Antagonists</style></keyword><keyword><style  face="normal" font="default" size="100%">Geniculate Bodies</style></keyword><keyword><style  face="normal" font="default" size="100%">In Vitro Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Models, Neurological</style></keyword><keyword><style  face="normal" font="default" size="100%">Neural Networks (Computer)</style></keyword><keyword><style  face="normal" font="default" size="100%">Neurons</style></keyword><keyword><style  face="normal" font="default" size="100%">Reaction Time</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptors, AMPA</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptors, GABA-A</style></keyword><keyword><style  face="normal" font="default" size="100%">Receptors, GABA-B</style></keyword><keyword><style  face="normal" font="default" size="100%">Stimulation, Chemical</style></keyword><keyword><style  face="normal" font="default" size="100%">Thalamus</style></keyword><keyword><style  face="normal" font="default" size="100%">Visual pathways</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000 Oct 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">20</style></volume><pages><style face="normal" font="default" size="100%">7478-88</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Thalamic circuits have an intrinsic capacity to generate state-dependent oscillations of different frequency and degrees of synchrony, but little is known of how synchronized oscillation is controlled in the intact brain or what function it may serve. The influence of cortical feedback was examined using slice preparations of the visual thalamus and computational models. Cortical feedback was mimicked by stimulating corticothalamic axons, triggered by the activity of relay neurons. This artificially coupled network had the capacity to self-organize and to generate qualitatively different rhythmical activities according to the strength of corticothalamic feedback stimuli. Weak feedback (one to three shocks at 100-150 Hz) phase-locked the spontaneous spindle oscillations (6-10 Hz) in geniculate and perigeniculate nuclei. However, strong feedback (four to eight shocks at 100-150 Hz) led to a more synchronized oscillation, slower in frequency (2-4 Hz) and dependent on GABA(B) receptors. This increase in synchrony was essentially attributable to a redistribution of the timing of action potential generation in lateral geniculate nucleus cells, resulting in an increased output of relay cells toward the cortex. Corticothalamic feedback is thus capable of inducing highly synchronous slow oscillations in physiologically intact thalamic circuits. This modulation may have implications for a better understanding of the descending control of thalamic nuclei by the cortex, and the genesis of pathological rhythmical activity, such as absence seizures.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">19</style></issue><custom1><style face="normal" font="default" size="100%">&lt;p&gt;http://www.ncbi.nlm.nih.gov/pubmed/11007907?dopt=Abstract&lt;/p&gt;
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