Do olfactory glia have advantages over Schwann cells for CNS repair?

To a large extent the success of axon regeneration and sustained remyelination which distinguishes the PNS from the CNS is attributable to differences in their respective glial environments. For this reason, many have been attracted to the idea that repair of the CNS might be achieved by transplanting Schwann cells into areas of CNS pathology. Schwann cells will not only promote regeneration but will also myelinate axons thereby making them an appropriate cell type to mediate repair of lesions characterised by demyelination as well as axotomy. The recent discovery that olfactory glia are capable of forming myelin sheaths, together with their well-documented ability to support axon regeneration, means that these cells have a range of repair properties similar to that of Schwann cells. It is not clear at present which of these two alternatives, the Schwann cells or the olfactory glial cell, would be of greater benefit for achieving regeneration of axons or remyelination of persistent demyelination following transplantation into the CNS. In this article we review the repair properties of olfactory glia and identify the areas in which their use for repairing the CNS may have advantages over Schwann cells.