C3 and Huntington disease: As a novel contribution, our results reveal an early expression of inflammatory cytokines and complement C3 at the level of the dentate nucleus and the neocerebellar cortex. This highlights that NPA administration primarily affects the more recent phylogenetic area of the rat cerebellum. Therefore, our experimental NPA model provides an alternate novel tool to study structure–function alterations of the cerebellum as a key target in the early stages of HD.