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Am J Physiol Regul Integr Comp Physiol. 2000 Jul;279(1):R295-305.

Increased expression of spinal cord Fos protein induced by bladder stimulation after spinal cord injury.

Author information

1
University of Vermont College of Medicine, Departments of Neurology and Anatomy and Neurobiology, Burlington, Vermont 05405, USA. mvizzard@zoo.uvm.edu

Abstract

These studies examined Fos protein expression in spinal cord neurons synaptically activated by stimulation of bladder afferent pathways after spinal cord injury (SCI). In urethan-anesthetized Wistar rats after SCI for 6 wk, intravesical saline distension significantly (P </= 0.005) increased the number of Fos-immunoreactive (IR) cells in the rostrolumbar (L1, 38 cells/section; L2, 29 cells/section) and caudal lumbosacral (L6, 140 cells/section; S1, 110 cells/section) spinal cord compared with control animals, but Fos expression in the L5 segment was not altered. The distribution of Fos-IR cells was also altered in the lumbosacral spinal cord. Significantly greater numbers of Fos-IR cells were distributed in the dorsal commissure and medial and lateral dorsal horn after intravesical distension in SCI animals. Large percentages of parasympathetic (75%) and sympathetic (85%) preganglionic neurons also expressed Fos-IR after intravesical distension in SCI animals. These results demonstrate that bladder distension produces increased numbers and an altered distribution pattern of Fos-IR cells after SCI. This pattern resembles that after noxious irritation of the bladder in control animals. Pretreatment with capsaicin significantly reduced the number of Fos-IR cells induced by bladder distension after SCI. These data suggest that SCI can reveal an altered Fos expression pattern in response to a nonnoxious bladder stimulus that is partially mediated by capsaicin-sensitive bladder afferents.

PMID:
10896894
DOI:
10.1152/ajpregu.2000.279.1.R295
[Indexed for MEDLINE]
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