Fish optic nerve oligodendrocytes support axonal regeneration of fish and mammalian retinal ganglion cells

Abstract

Segments from adult fish and rat retinae were explanted on myelinmarker expressing oligodendrocytes derived from the regenerating goldfish optic nerve. Fish axons grew in high density and even rat retinal axons regenerated to considerable length on the surface of the fish oligodendrocytes, suggesting that this type of fish glia has axon-growth promoting surface components that exert their influence across species boundaries, One interesting surface component of the fish oligodendrocytes as demonstrated here is the E 587 antigen, which is related to the L1 family of cell adhesion molecules.In long term cocultures of oligodendrocytes and retinal axons, the fish glial cells were found to enwrap rat axons. This suggests that the oligodendrocytes of the regenerating goldfish optic nervekract may, despite striking differences, represent the equivalent to mammalian optic nerve oligodendrocytes. Q 1993 Wiley-Lisa, Inc.

Expression of an L1-Related Cell Adhesion Molecule on Developing CNS Fiber Tracts in Zebrafish and Its Functional Contribution to Axon Fasciculation

“…E587 Ag possesses the unique feature of selectively clustering at cell-cell (Bastmeyer et al, 1993) and axonaxon contact sites in vitro (Bastmeyer et al, 1995). Whether this implies a function for axon-axon/cell-cell recognition is presently unknown.…”

Axon-Regenerating Retinal Ganglion Cells in Adult Rats Synthesize the Cell Adhesion Molecule L1 but Not TAG-1 or SC-1

“…Where glial cells are growth inhibiting, as in the mammalian CNS (Schwab et al, 1993), axonal regeneration fails to occur. Where they possess growth-promoting properties, as in the fish visual system (Bastmeyer et al, 1993;Wanner et al, 1995;Schwalb et al, 1996) and in the mammalian peripheral nervous system (PNS), severed axons regrow and restore lost functions (Gaze, 1970;Fawcett and Keynes, 1990).…”

Similarities and differences between fish oligodendrocytes and schwann cells in vitro

“…In contrast to mammals, myelin of the teleost CNS lacks such inhibitors Caroni and Schwab, 1988). Moreover, oligodendrocytes derived from the regenerating fish optic nerveltract acquire a state in which they favor the growth of regenerating (fish and rat retinal) axons along their surfaces (Bastmeyer et al, 1993) much a s PNS-derived Schwann cells do (Hopkins and Bunge, 1991;Morrissey et al, 1991). Accordingly, retinal ganglion cell (RGC) axons in warmblooded verte-6 1994 Wiley-Liss, Inc.…”

“…This was necessary in particular for oligodendrocytes of the adult goldfish optic nerveltract in vitro because these oligodendrocytes exhibit a morphology that is highly reminiscent of Schwann cells. Moreover, like PNS glia they carry adhesion molecules and promote axonal growth (Bastmeyer et al, 1993). Furthermore, like Schwann cells they increase in number for weeks in culture .…”

“…Within roughly 1 week in vitro, fish optic nerveltractderived oligodendrocytes (some of which have GFAPpositive fibrils) exhibit the early myelin marker 04 and concurrently 6D2 immunoreactivity (Bastmeyer et al, 1989. Although they lack more mature myelin markers, they do acquire spontaneously at least one of the typical fish myelogenic proteins, IP2 (Jeserich and Waehneldt, 1986;Bastmeyer et al, 19911, and enwrap rat axons in long-term co-cultures (Bastmeyer et al, 1993). We therefore consider them as, and term them, oligodendrocytes, although they have not completed their differentiation.…”