Grant: Project Grant

Forming memories of life's episodes is intimately linked to where these episodes took place. The same brain network is responsible for spatial navigation and memory formation, and it is no coincidence. Indeed, during sleep, the episodes are replayed, allowing the brain to form long lasting memories. Damages to these brain areas, either following strokes, malnutrition or neurodegeneration, often leads to debilitating conditions for the patients. This brain network is composed of interconnected areas. While the cortex has been the subject of extensive studies in the last four decades, in part because it is easy to access, much less is known about its main input: the thalamus. Yet, damages to the thalamus lead to disorders as severe as when the cortex is affected. As such, better understanding of deep brain circuits involved in memory and navigation is critical to help these patients. We will focus our work on one critical system for navigation and memory, the head-direction system, akin to the brain's compass. It orients the animals during wakefulness and actively participates to the consolidation of new memories during sleep. Here, to unravel the subcortical processes for spatial cognition and memory formation, we will leverage our expertise in precise recording technologies to monitor subcortical neuronal population in freely moving mice to elucidate how the head-direction signal is processed during wakefulness and sleep. To directly test the contribution of various neuronal populations, we will also use recently developed genetic tools making it possible to manipulate brain activity. This project will shed light on some of the most fundamental and evolutionary old networks supporting spatial cognition and memory formation in the brain and will open new avenues for the development of new diagnostic and therapeutic strategies.