Aberrant Synaptic Development: A Review

Recently, the use of the electron microscope has begun to reveal pathologic alterations of synapses accompanying certain neurologic disorders. For a thorough understanding of the significance of these alterations, synaptic morphology and development must be clarified. One useful tool in the armamentarium of synaptic morphologists is the ability to induce aberrant synaptic development, either through the use of various toxins, infectious agents, or, even more importantly, through the use of a large number of murine mutants such as “weaver.” One of the more common forms of synaptic aberrations in these experimental models is the development and retention of dendritic spines of Purkinje cells unattached to their normal presynaptic mates. A review of the morphologic details of this phenomenon, as well as some theoretical considerations regarding their implications, forms the body of the present article.