"Huntington’s disease (HD) is an inherited neurodegenerative disease, which has no cure, resulting from the mutation of the gene coding for huntingtin protein (htt). Clinically, HD patients present with progressive involuntary spasmodic movements and cognitive impairments. Post-mortem studies of HD patients reveal severe atrophy of the striatum, reflecting a selective neuronal loss of medium spiny neurons (MSNs). The path leading to MSNs death remains unknown. Conversely, astrocytic dysfunction might be a causal factor leading to HD pathogenesis. Astrocytes play 2 key roles in neuronal survival implicating glutamatergic transporters: supplying energy to the neurons (through a glycolytic flux) and regulating synaptic activity (mainly glutamatergic); and yet, both glucose consumption and glutamate regulation are altered in HD. To further study the specific role of astrocytes in the pathogenesis of HD, the host laboratory developed, using a lentiviral–based approach, the first in vivo mouse model which selectively expresses mutant htt in astrocytes. The main objective of this proposal is to gain new insights into the specific effect of astrocyte mutant htt expression on glutamate transporters and glycolytic metabolism. This objective will be achieved by pursuing a comprehensive characterization of this novel model (behavioral and neuropathological analyses using a stereological approach and detailed cell morphology analysis) and monitor the astrocytic function by combining techniques mastered by the applicant (electrophysiology) and by the host laboratory (glutamate receptors regulation and glucose utilization). Furthermore, defining the implication of altered astrocytes on neuronal loss would shed the light on the role of astrocytes in other neurodegenerative diseases."