Home Publications Controlling the oscillation phase through precisely timed closed-loop optogenetic stimulation: a computational study
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A. Witt, A. Palmigiano, A. Neef, A. El Hady, F. Wolf, and D. Battaglia (2013)

Controlling the oscillation phase through precisely timed closed-loop optogenetic stimulation: a computational study

Frontiers in Neural Circuits 7(49):1-17.  (export entry)


Dynamicoscillatorycoherenceisbelievedtoplayacentralroleinflexiblecommunicationbetweenbraincircuits.Totestthiscommunication-through-coherencehypothesis,experimentalprotocolsthatallowareliablecontrolofphase-relationsbetweenneuronalpopulationsareneeded.Inthismodelingstudy,weexplorethepotentialofclosed-loopoptogeneticstimulationforthecontroloffunctionalinteractionsmediatedbyoscillatorycoherence.Thetheoryofnon-linearoscillatorspredictsthattheefficacyoflocalstimulationwilldependnotonlyonthestimulationintensitybutalsoonitstimingrelativettheongoingoscillationinthetargetarea.Inducedphase-shiftsareexpectedtobestrongerwhenthestimulationisappliedwithinspecificnarrowphaseintervals.Conversely,stimulationswiththesameorevenstrongerintensityarelesseffectivewhentimedrandomly.Stimulationshouldthusbeproperlyphasedwithrespecttoongoingoscillations(inordertooptimallyperturbthem)andthetimingofthestimulationonsetmustbedeterminedbyareal-timephaseanalysisofsimultaneouslyrecordedlocalfieldpotentials(LFPs).Here,weintroduceanelectrophysiologicallycalibratedmodelofChannelrhodopsin2(ChR2)-inducedphotocurrents,basedonfitsholdingovertwodecadesoflightintensity.Throughsimulationsofaneuralpopulationwhichundergoescoherentgammaoscillations—eitherspontaneouslyorasaneffectofcontinuousoptogeneticdriving—weshowthatprecisely-timedphotostimulationpulsescanbeusedtoshiftthephaseofoscillation,evenattransductionratessmallerthan25%.Weconsiderthenacanoniccircuitwithtwointer-connectedneuralpopulationsoscillatingwithgammafrequencyinaphase-lockedmanner.Wedemonstratethatphotostimulationpulsesappliedlocallytoasinglepopulationcaninduce,ifpreciselyphased,alastingreorganizationofthephase-lockingpatternandhencemodifyfunctionalinteractionsbetweenthetwopopulations.