The extent of myelin pathology differs following contusion and transection spinal cord injury.
Demyelination is a prominent feature of spinal cord injury (SCI) and is followed by incomplete remyelination, which may contribute to physiological impairment. Demyelination has been documented in several species including humans, but the extent of demyelination and its functional consequence remain unknown. In this report, we document and compare the extent of tissue pathology, white matter apoptosis, demyelination, and remyelination 2 months following injury in rat contusion and transection models of SCI. Moreover, we document and compare the macrophage response 3 and 14 days post contusion and transection SCI. Contusion injury resulted in widespread tissue pathology, white matter apoptosis, demyelination, incomplete remyelination, and robust macrophage response extending several millimeters cranial and caudal to the epicenter of injury. In contrast, transection injury resulted in focal tissue pathology with white matter apoptosis, demyelination, incomplete remyelination, and robust macrophage response at the epicenter of injury, and little pathologic features at a distance from the epicenter of injury, as indicated by the lack of apoptosis and demyelination. These data indicate for the first time that myelin pathology differs substantially following contusion and transection SCI.
Siegenthaler
Monica M
MM
Reeve-Irvine Research Center, Departments of Anatomy and Neurobiology, College of Medicine, University of California at Irvine, Irvine, California 92697-4292, USA.
Tu
Michelle K
MK
Keirstead
Hans S
HS
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D019771:Axotomy; D003288:Contusions / Q000276:immunology / Q000473:pathology; D003711:Demyelinating Diseases / Q000209:etiology / Q000276:immunology / Q000473:pathology*; D005260:Female; D008264:Macrophages / Q000378:metabolism*; D009186:Myelin Sheath / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000276:immunology / Q000473:pathology*