This is a proposal to investigate the molecular components of the axonal plasma membrane particularly as they relate to the ensheathing glial cell. The molecular properties of premyelinated axolemma (isolated from newborn optic nerve), unmyelinated axolemma (isolated from the parallel fibers in the molecular layer of cerebellum and post myelinated axolemma (isolated from uniformly well-myelinated fibers in the pons, cerebellar peduncle or white matter of the cervical region of spinal cord) will be determined by HPLC separation and quantitative analysis of lipids and two dimensional separaton of proteins by polyacrylamide electrophoresis. A procedure will be developed to isolate the nodal axolemma from myelinated axons and its protein and lipid composition will be determined. Polyvalent antisera will be raised in rabbits to each isolated membrane fraction. If the antisera shows axonal plasma membrane specificity in situ the antisera will be used in conjunction with goat anti-rabbit coated polyacrylamide beads to specifically isolate and further purify an axonal plasma membrane fraction from each starting source. The molecular basis for the mitogenic effect of axolemma enriched fractions on cultured Schwann cells will be further investigated by solubilization and purification of the active molecule; the role of c-AMP in the mitogenic effect will also be investigated. It is anticipated that these studies will give new insights into specific axonal molecules required for neuron-glial interaction.
