NEURONAL PLASTICITY IN THE CEREBELLUM

Abstract

Publisher Summary The belief that the lesions of adult mammalian central nervous system (CNS) that are repaired only by reactive gliosis and that CNS neurons are incapable of regeneration had until recently the value of a dogma. The observation that adult mammalian neurons are capable of regeneration, of reactive synaptogenesis, and of formation of new circuits have far-reaching consequences, even if this capability is apparently limited to few neuron types. The remodeling of circuits in the adult can be considered as the response of neurones living in a stable environment, which has been destabilized by injury or by altered function. CNS development in mammals is not simply determined by a genetic code isomorphic with each structure to be formed but is the result of the interaction between genetically determined steps and epigenetic factors. An understanding of the relative contribution of the genetic and of the epigenetic in any sequence of phenomena occurring during development should guide toward a better knowledge of the possibilities of neuronal responses to environmental variations and should help in solving the contradiction that apparently exists between the concept of specificity and that of the plasticity of neuronal connections.