SCHWANN CELL-LIKE MYELINATION FOLLOWING TRANSPLANTATION OF AN OLFACTORY BULB-ENSHEATHING CELL-LINE INTO AREAS OF DEMYELINATION IN THE ADULTCNS

In this study we have transplanted a clonal olfactory bulb-ensheathing cell line into focal areas of the rat spinal cord which contain demye linated axons but neither oligodendrocytes nor astrocytes. The cell li ne was created by retroviral incorporation of the temperature-sensitiv e Tag gene into FAGS-sorted 04+ cells from 7-day-old rat pup olfactory bulb. The spinal cord lesions were obtained by injecting small volume s of ethidium bromide into the dorsal white matter of spinal cord prev iously exposed to 40 Grays of X-irradiation. Many of the axons were re myelinated by P0+ myelin sheaths 21 days after transplantation. Light and electron microscopy revealed cells engaging and myelinating axons in a manner highly reminiscent of Schwann cells within similar lesions . GFAP+ cells were also present within the lesion. This study provides the first in vivo evidence that olfactory bulb-ensheathing cells are able to produce peripheral-type myelin sheaths around axons of the app ropriate diameter. (C) 1996 Wiley-Liss, Inc.