title: Increased expression of spinal cord Fos protein induced by bladder stimulation after spinal cord injury.
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.
authors.affiliation: University of Vermont College of Medicine, Departments of Neurology and Anatomy and Neurobiology, Burlington, Vermont 05405, USA. mvizzard@zoo.uvm.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Vizzard
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage; D000283:Administration, Intravesical; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000378:metabolism; D002211:Capsaicin / Q000008:administration & dosage; D002452:Cell Count / Q000187:drug effects; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D008161:Lumbosacral Region; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000201:enzymology; D009929:Organ Size / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000008:administration & dosage; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000378:metabolism*; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology*; D014551:Urinary Tract / Q000187:drug effects
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D012965:Sodium Chloride; D002795:Choline O-Acetyltransferase; D019342:Acetic Acid; D002211:Capsaicin