CRYO-IMMUNOGOLD ULTRASTRUCTURAL-LOCALIZATION OF LAMININ IN ADULT-RAT PERIPHERAL-NERVE

Elucidation of the functional roles of the extracellular matrix compon ent laminin in adult peripheral nerve has been hindered by differing a ccounts of its ultrastructural localization. This is the first report applying the advantages of the cryo-immunogold technique to laminin lo calization in peripheral nerve. Laminin labelling was found over the b asal lamina and possibly over the immediately subjacent Schwann cell p lasma membrane, but specific labelling appeared to be absent from othe r membranes (including those of non-myelinated axon/Schwann cell clust ers) and from endoneurial collagen fibrils. It would appear that the f unctional roles played by laminin in normal adult peripheral nerve are likely to be mediated via its localization in the basal lamina, rathe r than through a more widespread distribution within the endoneurium.