Synaptic Specificity in the Cerebellar Cortex: Study of Anomalous Circuits Induced by Single Gene Mutations in Mice

In recent years, neuroanatomical and electrophysiological methods have been refined to allow identification of specific classes of synaptic contacts. These methods have demonstrated that the mammalian central nervous system has a substantial capacity for synaptic reorganization following localized lesions produced by various external agents. However, the capacity for synaptic reorganization in different brain structures has not been clearly defined. The analysis of synaptic organization in mice as modified by the consequences of a single gene mutation offers a useful model for the study of structural plasticity in different regions of the central nervous system. Genetic models of synaptic rearrangement have an advantage over most of the environmental agents that have been employed because mutation may affect only a specific population of cells without necessarily directly disturbing other components in a given synaptic circuitry. Admittedly, the use of genetic mutations does not permit direct control over the degree or timing of...