Contusive spinal cord injury evokes localized changes in NADPH-d activity but extensive changes in Fos-like immunoreactivity in the rat.
The histological detection of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d), a marker for nitric oxide-producing cells, was used to evaluate ongoing changes in the neural biochemistry of the rat spinal cord 1 week following contusive spinal cord injury (SCI). In addition, the immunohistochemical detection of the immediate-early gene c-fos was used to identify basal patterns of neural activity at this time. The numbers and laminar locations of NADPH-d- and c-fos-positive cells were examined in spinal segments adjacent to the site of injury (T12-S3) as well as those distant from the injury (C3-C5) in both SCI and un-injured rats. Our data show that contusive SCI results in a significant reduction in NADPH-d labelling in the superficial dorsal horn, and a significant increase in NADPH-d expression in small bipolar neurons and large motoneurons in the ventral horn at the site of the injury. In spinal segments distant to the injury site (C3-C5), NADPH-d activity did not differ from that of uninjured controls. Furthermore, significant reductions in the levels of c-fos expression were observed in SCI rats, in spinal segments both at and distant to the site of injury for all spinal laminae. The only exception was a dramatic increase observed in the sacral parasympathetic nucleus. These data suggest that increased NADPH-d expression is related to conditions specific to the site of injury, whereas the changes in c-fos expression probably indicate more global changes in neuronal activity following SCI.
Allbutt
Haydn N
HN
School of Medical Sciences (Anatomy & Histology), University of Sydney, Australia. hall@physiol.usyd.edu.au
Siddall
Phillip J
PJ
Keay
Kevin A
KA
D000818:Animals; D001522:Behavior, Animal; D015415:Biomarkers / Q000032:analysis; D003288:Contusions / Q000378:metabolism* / Q000473:pathology; D005260:Female; D007150:Immunohistochemistry; D007395:Interneurons / Q000737:chemistry / Q000378:metabolism; D009046:Motor Neurons / Q000737:chemistry / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000032:analysis*; D009569:Nitric Oxide / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology; D013194:Staining and Labeling; D013997:Time Factors
D015415:Biomarkers; D016760:Proto-Oncogene Proteins c-fos; D009569:Nitric Oxide; D009252:NADPH Dehydrogenase