Seminar on ' Macroscopic Phase Resetting-curves Determine Oscillatory Coherence and Signal Transfer in Inter-coupled Neural Circuits '
On December 13, 2019 an Applied Geometry and Topology Lab’s seminar will be held at HSE.
Boris Gutkin (L'École normale supérieure & Institute of Cognitive Neuroscience HSE) will speak on 'Macroscopic phase resetting-curves determine oscillatory coherence and signal transfer in inter-coupled neural circuits'.
Macroscopic oscillations of different brain regions show multiple phase relationships that are persistent across time and have been implicated in routing information. While multiple cellular mechanisms influence the network oscillatory dynamics and structure the macroscopic firing motifs, one of the key questions is to identify the biophysical neuronal and synaptic properties that permit such motifs to arise. A second important issue is how the different neural activity coherence states determine the communication between the neural circuits. We analysed the emergence of phase-locking within bidirectionally delayed-coupled spiking circuits in which global gamma band oscillations arise from synaptic coupling among largely excitable neurons. We considered both the interneuronal (ING) and the pyramidal-interneuronal (PING) population gamma rhythms and the inter coupling targeting the pyramidal or the inhibitory neurons. Using a mean-field approach together with an exact reduction method, we reduced each spiking network to a low dimensional nonlinear system and derived the macroscopic phase resetting-curves (mPRCs) that determine how the phase of the global oscillation responds to incoming perturbations. From there we derived a phase coupling euqation for interconnected circuits and determined the structure of macroscopic coherence states (phase-locking) of two weakly synaptically-coupled networks. We showed that a synaptic transmission delay is a necessary condition for symmetry breaking, i.e. a non-symmetric phase lag between the macroscopic oscillations. This potentially provides an explanation to the experimentally observed variety of gamma phase-locking modes. Our analysis further showed that symmetry-broken coherence states can lead to a preferred direction of signal transfer between the oscillatory networks where this directionality also depends on the timing of the signal. Hence we suggest a causal theory for oscillatory modulation of functional connectivity between cortical circuits.
Start time: 6:10 pm
Location: 11 Pokrovsky Boulevard, room R 205
Seminar working language – English
If you need a pass to the building please contact Zherebtsova Ksenia via email firstname.lastname@example.org