On the cerebello-cerebral interactions.

The question of which type of information and how it is being processed by the puzzling cerebellar circuitry remains open. Numerous works have highlighted and delineated the roles of cerebellar pathways in various parameters of motor control, such as timing of motor commands. Recent anatomical and functional data on a possible genuine cerebellar contribution in the processing of 'cognitive', behavioral and emotional information have not yet generated a consensus. Despite an apparent homogeneous and uniform cytoarchitecture, the actors of the cerebellar orchestra do play different roles depending on the anatomical inputs/outputs of the cerebellar regions. The numerous interactions between the cerebellum and the cerebral cortex remain a major field of research. Fundamental questions related to the cerebro-cerebellar networks, such as the modulation of corticomotoneuronal discharges in various contexts, have not been fully addressed, or only indirectly, with recent methods. Complexity of circuitries and non optimal theoretical frameworks continue to hamper our understanding of cerebellar operations.