Cell replacement in the degenerating cerebellum: a historical essay of discovery.

The article revisits neurobiological experiments conducted over the past 50 years, aimed at deciphering questions of cerebellar development and plasticity, and the integration of primordial cerebellar tissue into host brains by means of intracerebral transplantation. The recipient organisms have primarily been normal rodents or mice with genetic mutations affecting the cerebellar cytoarchitecture, as models of human ataxias. Emerging issues in basic neuroscience research regarding neuron replacement or rescue using diverse tissue sources, as well as possible ways to prevent neuron loss through pharmacological and genetic engineering approaches, are also highlighted.