Investigation of phase-locked neuronal oscillation with optical stimulation based on a time-frequency approach

Over the past few years, optical neural stimulation using optogenetics has drawn much attention in neuroscience and biomedical engineering communities because of its many advantages over electrical stimulation. Despite significant amount of studies regarding the effects of optical stimulation on neural activities, the influence of optical stimulation on a large neural population is overlooked. Neuronal oscillation is a fundamental component of brain function and is believed to play an important role in large-scale neuronal computations. This paper investigates the effects of the optical stimulation on neuronal oscillations in rat´s primary visual cortex, by comparing ECoG signals evoked via visual stimulation and cortically optical stimulation. A newly developed Opto-μECoG array, a hybrid neural interface with transparent μECoG electrodes and integrated LEDs, was used to deliver a cortically optical stimulation and record ECoG signals simultaneously. The recorded ECoG signals were analyzed using a conventional instantaneous phase estimation based on the Hilbert Transform and a new time-varying phase synchrony measure based on reduced interference distribution time-frequency phase synchrony (RID-TFPS).