Antoine Madar

Antoine Madar
Ph.D. Candidate


Mathew V. Jones

Research Description:

My research interests lie in understanding how groups of brain cells process information and how the activity of neuronal networks gives rise to cognitive faculties such as memory.

In Mathew Jones’ lab, I focus on the role inhibitory neurons play in shaping the electrical activity of granule cells, the excitatory output neurons of the dentate gyrus of the hippocampus.

The hippocampus is of major importance for formation, storage and recall of memories. These are thought to be temporarily stored in area CA3 of the hippocampus, an “auto-associative network” that can recall learned electrical patterns from partial cues. This recall is possible because of the recurrent and plastic excitatory connections in area CA3. However, this strong recurrent excitation also creates two major problems: it predisposes the hippocampus to epileptic seizures, and it severely limits the number of patterns that can be stored without overlap and interference. A solution to both of these problems is to add a pre-processing gate that performs "pattern separation" before sending the orthogonalized patterns of activity to CA3. Although theoretical and experimental in-vivo work suggests that the dentate gyrus does perform this role, the mechanisms leading to such a role remain unclear. To clarify these processes, I use acute slices of mice brain to perform either whole-cell patch-clamp recordings or multi-electrodes array recordings while stimulating the perforant pathway to simulate trains of inputs to the hippocampus. My project is to determine how interneurons in the dentate gyrus may act to selectively regulate the activity across the population of granule cells, thus transmitting to CA3 only the most distinctive aspects of the incoming input.