CaRe-Space · Cajal-Retzius cells role in the development of the spatial navigation system

Cajal-Retzius (CR) cells play a pivotal role in the development of cortical areas, by guiding the migration of principal cells. While cortical CR cells disappear soon after birth, these cells are present in the hippocampus for several months of postnatal development. However, the role that CR cells play in hippocampus-dependent memories is still unknown. In fact, thehippocampal-parahippocampal region forms a network responsible for spatial representation, in rodents and in humans. In both species, spatial navigation shows a delayed postnatal maturation, which correlates with the persistence of CR cells. CR cells are indeed located in a key position to control the development of the entorhinal-hippocampal connections, and I have previously showed that CR cells are an active part of the hippocampal circuit. I hypothesize that hippocampal CR cells play afundamental role in the maturation of the circuits of the hippocampal region and in the development of the spatial navigation system. By using specific genetic and molecular tools, I will ablate hippocampal CR cells at early postnatal stages and then analyze alterations of the circuit of the hippocampal region and of the spatial navigation system.The last decade has seen a major global effort in trying to understand how the brain processes information. Indeed, several research groups are investigating how spatial maps are created in the brain. However, few studies have looked at how the involved circuits actually develop and what are the consequences of an improper maturation. My previous researchexperience on the development of neuronal circuits and specifically on CR cells will benefit me tremendously in understanding how these cells are contributing to the creation of spatial memory. The study will also help bridging a gap between developmental and system neuroscience, a goal that I will keep pursuing in my future scientific career.