Dr. Ohara has received funding from the National Multiple Sclerosis Society to study the mechanims of Schwann cell remyelination of the spinal cord in a rodent model we have recently developped (Jasmin, L. et al. (2000) Schwann cells are removed from the spinal cord after effecting recovery from paraplegia. J Neurosci 20, 9215-9223.)

Background

Chronic CNS demyelination ( loss of oligodendrocytes the myelinating cells in the CNS) be the result of a number of conditions such as:

  • Multiple Sclerosis
  • Post-injury (mechanical or vascular)
  • Post-irradiation

Why remyelinate the CNS with Schwann cells? Just as neurons in the CNS have a limited capacity for spontaneous repair so too do the oligodendrocytes not have a robust regenerative capacity. This is due both the finite number of oligodendrocyte progenitors, and their limited capacity for migration.
Compared to oligodendrocytes , Schwann cells

  • migrate further and faster
  • divide more
  • remyelinate faster
  • are more resistant to injury
  • may not be affected by the immune processes responsible by central demyelination

There is evidence for Schwann cells remyelination of the CNS under particular circumstances. Schwann cell remyelination can occur:

  • spontaneously, as seen in MS patients, in animal models of demyelination (Chemically induced , Experimental allergic encephalomyelitis (EAE)), in spinal cord injury (contusion, ischemia, heat), and in myelin deficient animals
  • after transplantation