Salk Institute / UCSD / Nature Medicine 2005 Symposium:

Stem Cell Biology & Human Disease

"A Novel Pathogenic Mechanism in Chronic Spinal Cord Injury: Progressive Disruption of a Glial Stem/Progenitor Niche"

Author: Milan Radojicic MD

Chronic spinal cord injury is a well-known clinical entity that can lead to an insidious decline in motor and sensory function in patients even years after the initial injury.  Anatomically, chronic spinal cord injury may be accompanied by a progressive dilation of glial-lined cysts of the central spinal cord, known as syringomyelia, and the histologic features of this disease share many characteristics with chronic hydrocephalus.  Moreover, recent work has demonstrated that chronic demyelination accompanies chronic spinal cord injury.  Taken together, this work suggests that chronic spinal cord injury is in many respects a neurodegenerative disorder, but little is known about the pathogenesis of late stages of the disease and sequence of events in disease evolution remains a mystery.  It is intriguing to note that the central canal of the spinal cord is known to contain glial stem/progenitor cells that give rise to new ependymal cells, astrocytes, oligodendrocytes and microglia.  Here, I undertook a histologic study of rats with chronic spinal cord injury in hopes of elucidating some novel features of the disease.  We witnessed an ascending progressive dilation of the central canal, presumably due to distensile forces within the canal, that resulted in a distinct pattern of phenotypic changes of the cells lining the cavity.  I hypothesize that the progressive disruption of this cell layer, the probable location of a glial stem/progenitor cell niche, should be considered in the pathogenesis of spinal cord injury.

Copyright 2004 Milan Radojicic MD.  All rights reserved.