Fig. 1

Cerebellum detects similarities and discordances between predicted and actual sequences of events. The incoming sensation activate a microcomplex especially via activation of mossy fibres (MFs). Selected bands of Purkinje neurons are activated, resulting in a sculpting of patterns in the cerebellar nuclei. In case of discrepancy between actual signals and expected sequence, the forward model is recalibrated via activation of the climbing fibres (CFs) of the olivo-cerebellar tract. Right panel: schematic representation of the cerebellar circuitry. Parallel fibres emerging from granule cells (in orange) generate simple spikes (S. Sp.) at the level of Purkinje neurons (in black). Purkinje neurons target cerebellar nuclei neurons (in green). The activation of the inferior olivary complex (in blue) triggers a complex spike in the cerebellar cortex