Phase diversity and synchronized oscillation between neuronal populations
Neuronal heterogeneity is a fundamental feature of the nervous system and is especially prominent among cortical inhibitory populations. Although such variability might be expected to disrupt synchrony, cortical circuits can still generate coherent oscillations during cognitive processes. This raises the question of how neuronal diversity shapes brain dynamics. In parallel, the study of intrinsic brain activity has revealed Resting-State Networks, spatially distributed and functionally connected regions that remain active in the absence of external stimuli. A hallmark of RSNs is the emergence of synchronized oscillations, particularly in the alpha band (~10 Hz), which are thought to support long-range cortical communication.
Here, we first study how inhibitory heterogeneity affects inter-areal phase relationships. Using the Izhikevich model, we analyze how different inhibitory neuron types modulate the phase dynamics between two unidirectionally coupled neuronal populations. Our results show that inhibitory diversity can alter phase relationships even when the global excitatory/inhibitory balance is preserved.
We also examine two reciprocally connected populations of 100 Adaptive Exponential Integrate-and-Fire neurons. This model robustly generates highly synchronized alpha-band oscillations. By varying coupling strength, we identify conditions for the emergence and maintenance of synchrony, and show that alpha power can be enhanced by weak sinusoidal input.
This Annual PhD student seminar will be broadcasted in the following zoom link: https://us06web.zoom.us/j/89466064429?pwd=po9p99eAEYVPaNI8xIIGoOIz0hOqaF.1
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