title: Distributed Circuit Plasticity: New Clues for the Cerebellar Mechanisms of Learning.
abstract: The cerebellum is involved in learning and memory of sensory motor skills. However, the way this process takes place in local microcircuits is still unclear. The initial proposal, casted into the Motor Learning Theory, suggested that learning had to occur at the parallel fiber-Purkinje cell synapse under supervision of climbing fibers. However, the uniqueness of this mechanism has been questioned, and multiple forms of long-term plasticity have been revealed at various locations in the cerebellar circuit, including synapses and neurons in the granular layer, molecular layer and deep-cerebellar nuclei. At present, more than 15 forms of plasticity have been reported. There has been a long debate on which plasticity is more relevant to specific aspects of learning, but this question turned out to be hard to answer using physiological analysis alone. Recent experiments and models making use of closed-loop robotic simulations are revealing a radically new view: one single form of plasticity is insufficient, while altogether, the different forms of plasticity can explain the multiplicity of properties characterizing cerebellar learning. These include multi-rate acquisition and extinction, reversibility, self-scalability, and generalization. Moreover, when the circuit embeds multiple forms of plasticity, it can easily cope with multiple behaviors endowing therefore the cerebellum with the properties needed to operate as an effective generalized forward controller.
authors: Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy. dangelo@unipv.it.|Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy. dangelo@unipv.it.
authors: Egidio
authors: E
authors: D'Angelo
authors: Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.|Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome, Italy.
authors: Lisa
authors: L
authors: Mapelli
authors: Department of Bioengineering, Politecnico of Milano, Milano, Italy.
authors: Claudia
authors: C
authors: Casellato
authors: Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.|Department of Computer Architecture and Technology, University of Granada, Granada, Spain.
authors: Jesus A
authors: JA
authors: Garrido
authors: Department of Computer Architecture and Technology, University of Granada, Granada, Spain.
authors: Niceto
authors: N
authors: Luque
authors: Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy.
authors: Jessica
authors: J
authors: Monaco
authors: Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
authors: Francesca
authors: F
authors: Prestori
authors: Department of Bioengineering, Politecnico of Milano, Milano, Italy.
authors: Alessandra
authors: A
authors: Pedrocchi
authors: Department of Computer Architecture and Technology, University of Granada, Granada, Spain.
authors: Eduardo
authors: E
authors: Ros
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D013569:Synapses / Q000502:physiology*
keywords: Cerebellum; Distributed plasticity; LTD; LTP; Learning; Long-term synaptic plasticity; Memory