Characterization of novel set of membrane antigens associated with axonal growth. III: Expression in the regenerating goldfish optic nerve and tectum.
In the preceding two papers in this series, a polyclonal antiserum (3070) and several monoclonal antibodies (MAbs 4 and 199) were used to define a novel set of laminin-binding membrane antigens in chick brain. In chick brain, 3070 and MAb 4 antigens stained growing axons and migrating nascent neurons transiently; though projection neurons were intensely labelled at all stages, normal glial cells were stained faintly or not at all. To learn if these antigens are associated more generally with active states of nerve growth, the present paper examined the expression of 3070 and MAb 4 antigens during regeneration of the goldfish optic nerve. Only a few optic fibers or glial cells were stained by 3070 antiserum in the resting (uninjured) optic nerve, but 10 days following a unilateral nerve crush, when the growth response is maximal in these fish, distal regenerating neuritic sprouts and glial cell bodies and processes were profusely labelled. The intensity of labelling was diminished by 135 days post-crush, when most active growth was completed. Since 3070/MAb 4 antigens exhibit properties expected for functional laminin receptors, these findings suggest several possible roles that they could play to aid nerve regeneration.