Grant: Project Grant

We spend a third of our lives sleeping, yet the role of sleep remains largely unknown. During sleep, the mammalian brain shows specific oscillations that are not observed during wakefulness. It is believed that the interplay between high frequency oscillations in the hippocampus, a key brain area for memory, and the so-called sleep spindles in the neocortex plays a key role in the formation of long-term memories. However, the changes in neuronal dynamics observed during sleep make the brain more prone to epileptic activity. In the epileptic brain, high frequency oscillations are associated with abnormal electrical activity in affected tissues. Interestingly, they are also coupled to spindles, which may play a protective role against the propagation of epileptiform activity. The goal of this project is to gain mechanistic neurobiological insights into the coupling between high frequency oscillations and spindles. Specifically, by monitoring and manipulating ensembles of neurons across brain structures in control and epileptic mice, we will test the hypothesis that the neuronal circuits and dynamics underlying this coupling are the same in the healthy and epileptic brain and that this dynamical interaction is a necessary phenomenon for learning in health and for the protection of healthy tissue against epileptic discharge. In addition, we will test the neuronal basis of this coupling in epileptic subjects implanted with intracranial electrodes. This project will shed light on one of the fundamental dynamical patterns of the sleeping brain.