Soft Matter Seminar: Prof. Antonio Fernandez Ruiz

Professor Antonio Fernandez Ruiz, Department of Neurobiology and Behavior, Cornell University

“Role of oscillations and synchrony in neuronal information processing”

Abstract: Oscillatory dynamics are ubiquitous signatures of operating neural circuits. Multiple types of oscillations have been described across animal species and neural structures, being commonly associated with a large array of behaviors, computations, and codes, in the sensory, cognitive, and motor domains. Notably, high-frequency oscillations in brain cortical areas, have been related to action potential timing, neuronal population synchrony and cross-structural communication channels for selective processing and routing of information. Yet, despite the wealth of research on this topic, whether brain oscillations represent mere readouts or causal mechanisms of neural operations remains unclear, and a unifying view is still missing.
The hippocampus and associated cortical structures play a key role in learning and memory processes. The synchronous spiking of cell ensembles in these circuits supports the encoding and recall of behaviorally relevant information, while neural oscillations coordinate inter-areal communication. In the first part of the talk, I will present novel evidence on the role of gamma frequency oscillations in coordinating the precise synchronization of neuronal activity across brain region to support flexible learning.

Neurons that have been active during a recent experience are reactivated during high frequency network oscillations known as sharp-wave ripples (SWRs). This “replay” of behaviorally relevant sequences during SWRs after a new experience is believed to mediate memory maintenance and behavioral planning. In the second part of the talk, I will provide causal evidence on how the sequential reactivation of neuronal ensembles during SWRs contribute to memory.