[Dysfunction of central gray nuclei]

We first recall the anatomical organization of the basal ganglia system (or central grey nuclei), putting forward their macroscopical, hodological and cytological properties and the convergent properties that arise from them. Then we examine the different functional models that have been developed since the eighties, the convergent model in 1984, the parallel model in 1986, the dual circuit in 1989, the "current" model in 1990, and the critics of the latter since 1993. We finally sum up the recent models developed since the nineties.