Olfactory ensheathing cells: potential for glial cell transplantation into areas of CNS injury.

Ensheathing cells are the glial cells that ensheath olfactory axons within both the PNS and CNS portions of the primary olfactory pathway. These glial cells express a mixture of astrocyte-specific and Schwann cell-specific phenotypic features, support axonal growth by olfactory as well as by non-olfactory neurons, and survive transplantation into injured areas of the CNS. This review article focuses on those phenotypic features that are expressed by ensheathing cells that make them ideal candidates for transplantation into wound cavities in the damaged spinal cord of humans. Although much work remains to be done before such a therapeutic approach can be tried, the likelihood that ensheathing cells could simultaneously perform the roles of both astrocytes and Schwann cells following transplantation is the justification for developing such a therapeutic approach using animal models of spinal cord injury.