RT Journal Article SR Electronic T1 Schwann Cells Are Removed from the Spinal Cord after Effecting Recovery from Paraplegia JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 9215 OP 9223 DO 10.1523/JNEUROSCI.20-24-09215.2000 VO 20 IS 24 A1 Luc Jasmin A1 Gabriella Janni A1 Theodore M. Moallem A1 Douglas A. Lappi A1 Peter T. Ohara YR 2000 UL http://www.jneurosci.org/content/20/24/9215.abstract AB Remyelination of the CNS is necessary to restore neural function in a number of demyelinating conditions. Schwann cells, the myelinating cells of the periphery, are candidates for this purpose because they have more robust regenerative properties than their central homologs, the oligodendrocytes. Although the ability of Schwann cells to remyelinate the CNS has been demonstrated, their capacity to enter the adult spinal cord in large numbers and effect functional recovery remains uncertain. We used cholera toxin B-subunit conjugated to saporin to demyelinate the rat lumbar spinal cord, remove macroglia, and produce paraplegia. After the removal of oligodendrocyte and astrocyte debris by invading macrophages, there was a spontaneous entry of Schwann cells into the spinal cord, along with axonal remyelination and concomitant functional recovery from paraplegia occurring within 75 d. The Schwann cells appeared to enter the dorsal funiculi via the dorsal root entry zone and the lateral funiculi via rootlets that had become adherent to the lateral spinal cord after the inflammation. In the following weeks, Schwann cell myelin surrounding central axons was progressively replaced by oligodendrocyte myelin without lapse in motor function. Our results show that endogenous Schwann cells can reverse a severe neurological deficit caused by CNS demyelination and enable later oligodendrocyte remyelination.