MOLECULES THAT BECOME REDISTRIBUTED DURING REGENERATION OF THE LEECH CENTRAL-NERVOUS-SYSTEM

A search has been made for molecules other than laminin that change th eir distribution during axonal regrowth after injury. Two monoclonal a ntibodies, generated against a protein extract of leech central nervou s system (CNS), stain distinct regions of leech CNS and, following les ions, show changes in distribution with time. 1. Monoclonal antibody N P17 stained two hands of M(r) 80x10(3) and 60X10(3) on Western blots o f protein extracted from whole CNS. On cryosections of leech CNS, stai ning was predominantly within the neuropile. 2. A second antibody, mAb CT16, stained a collagen-associated molecule of the extracellular mat rix. It labelled the outer capsule, which surrounds the neuronal cell packets, and the inner capsule, which envelops the neuropile. In the c onnectives, CT16 immunoreactivity was restricted to the connective cap sule and was not associated with nerve fibres or glia. 3. When the con nectives were crushed, immunocytochemical studies revealed changes in distribution of both mAb NP17 and mAb CT16. After 3 days, a time when fibres begin to sprout and form connections, an increase in NP17 immun oreactivity appeared at the site of the lesion. Staining levels remain ed elevated for several weeks. In contrast, CT16 immunoreactivity did not change for several days after damage. After 10 days, fibre-like st aining appeared at the site of the crush; for several weeks it continu ed to spread throughout the connective. 4. These results show that reg eneration of the leech CNS involves the redistribution of at least two molecules. Using monoclonal antibodies, these two molecules, which ar e situated in distinct regions of the CNS, have been visualized at dif ferent stages of the repair process. It has been shown that they alter their distribution at distinct times during regeneration.