PERIPHERIN AND NEUROFILAMENTS - EXPRESSION AND ROLE DURING NEURAL DEVELOPMENT

This review focuses attention on the expression of peripherin and the low-molecular mass neurofilament protein during development, as well a s on recent results concerning the roles of these neuronal proteins. P eripherin is the only type III intermediate filament that has been sho wn to be expressed in neurons but exclusively in motor, sensory and sy mpathetic neurons ; moreover, it is co-expressed with neurofilament pr oteins (NFP). Clearly, peripherin is expressed concomitantly with axon al growth during development, and its synthesis appears necessary to a xonal regeneration in the adult. As to NFP, they are presumed to maint ain the axonal diameter and thereby ensure a normal conduction velocit y. In many neuropathies, either occurring in man or provoked by differ ent means in animals, the neurofilament network is disrupted thus givi ng rise to bundles of filaments in perikarya or along axons ; conseque ntly, the axonal transport is impaired. The possible significance of t he overexpression of NFP is discussed.