Development of the cerebral cortex and adult hippocampal neurogenesis are complex processes where huntingtin, the protein mutated in Huntington disease, plays a central role. Understanding these mechanisms will open new avenues potentially leading to treatment of Huntington disease and other neuropathologies.

Our overall goal is to understand the mechanisms coordinating division, cell fate choices and differentiation of neuronal stem/progenitor cells during development and adulthood. We are tackling these issues through the study of one protein, huntingtin. Huntingtin is the perfect model protein, being a scaffold for complexes involved in spindle orientation, cell-cell junctions and cell polarization. Furthermore, huntingtin is mutated in Huntington disease, an inherited neurodegenerative disorder with adult onset. Studying huntingtin thus allows integration of cellular mechanisms and physiological and pathophysiological conditions.

More specifically, we are studying the contribution of huntingtin to different steps of cortical development and adult hippocampal neurogenesis. We aim to define the molecular complexes involved. We also address the questions of how these mechanisms participate in the proper establishment and maintenance of neuronal networks and whether these pathways are altered in Huntington disease. Our working hypothesis is that abnormal development could be a predisposing factor contributing to the symptoms observed in Huntington disease. In the adult, we propose that the depressive behaviour observed in patients is not just an epiphenomenon to a severe disorder with a fatal outcome, but the result of a modification in the biological function of huntingtin in adult neurogenesis.

GIN – Inserm U1216 – University Grenoble Alpes

Lab members: Fabienne Agasse; Monia Barnat; Barbara Braz; Caroline Benstaali; Mariacristina Capizzi; Rémi Carpentier; Julien Le Friec; Elodie Martin; Doris Wennagel.