Striatal projection neurons are one of the most affected neuronal populations in Huntington´s disease (HD). These neurons undergo structural and functional changes, and eventually die. Our project aims at investigating the early degenerative changes of striatal neurons in experimental models of HD. To this end we have set up an in vitro model to address the structural maturation of striatal neurons and their response to neurotransmitters present in the striatum in vivo. In one first project we shall examine the effects of mutant huntingtin on the structure and function of striatal neurons in these cultures. We shall next use transgenic mouse models of HD to see whether their striatal neurons show alterations similar to those seen in the culture model, and whether these alterations correlate with the development of behavioural disorders.