This book encompasses basic and clinical reports on the cerebellum and its primary atrophic disorders, the cerebellar degenerations. Rapid progress has been made in understanding the organization and function of the cerebellum at the neuronal, synaptic and molecular level. Of particular importance has been the identification of the chemical transmitters utilized by the cerebellar cellular systems. More then any other brain region, the cerebellum utilizes amino acids as its main excitatory and inhibitory neurotrasmitters. Excitatory amino acid transmiters, in addition to serving neuronal communication, may also mediate trophic and toxic effects and, as such, they may play a role in neurodegenerative processes. This volume should be useful to clinicians who care for patients with cerebellar disorders as well as to the basic and the clinical investigators whose work concerns the cerebellum. Knowledge of advances occurring in basic sciences will help the clinical investigator to develop new approaches and therapeutic strategies for these presently intractable human disorders. Also the basic investigator will benefit from the study of human disorders by identifying new research leads provided by these intractable - yet fascinating - afflictions.