title: Efficacy of neuroselective and site-specific nociceptive stimuli of rat bladder.
abstract: OBJECTIVE
  To evaluate the organ specificity of sine wave electrical stimulation of the bladder through assessment of the expression of Fos-immunoreactive (IR) cells in rat spinal cord regions.
  
  
  METHODS
  A total of 37 female Sprague-Dawley rats were divided into 8 groups: sham stimulation; 5, 250, and 2000 Hz stimulation with 1.5- or 2.0-mA intensity; and a group instilled with capsaicin in the bladder. Using a recently developed bladder sensory threshold device, sine wave electrical stimulation was applied for 90 minutes to the rat bladder. The spinal cord was harvested after the rats were killed. The Fos-IR cells in the spinal regions of the medial dorsal horn, lateral dorsal horn, dorsal commissure, and sacral parasympathetic nucleus were measured. The distributions of the Fos-IR neurons were compared.
  
  
  RESULTS
  The maximal expression of Fos-IR cells, induced by 250- and 5-Hz stimulation of the bladder, was found at L6 of the spinal cord and was significantly greater than that in the control group (P<.01). Stimulation with 2000 Hz did not induce any Fos-IR cells. Fos-IR neurons were predominantly seen in the sacral parasympathetic nucleus region in response to 250-Hz stimulation and in the dorsal commissure region in response to 5-Hz stimulation. The number of positive neurons was similar to the number caused by capsaicin instillation.
  
  
  CONCLUSIONS
  Frequency-specific sine wave electrical stimulation of the rat bladder induced the expression of Fos-IR cells in a neuroselective manner. The bladder sensory threshold device could be used for exploration of the pathophysiology of diseases with disturbances of the afferent pathway of the bladder.
authors.affiliation: Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamada
authors.forename: Osamu
authors.initials: O
authors.lastname: Ukimura
authors.forename: Guiming
authors.initials: G
authors.lastname: Liu
authors.forename: Tsuneharu
authors.initials: T
authors.lastname: Miki
authors.forename: Firouz
authors.initials: F
authors.lastname: Daneshgari
mesh_terms: D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D004558:Electric Stimulation / Q000009:adverse effects; D004567:Electrodes, Implanted; D005260:Female; D005786:Gene Expression Regulation; D017781:Genes, Immediate-Early; D016762:Genes, fos; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D059225:Nociception / Q000502:physiology*; D009928:Organ Specificity; D010275:Parasympathetic Nervous System / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012684:Sensory Thresholds; D013116:Spinal Cord / Q000473:pathology*; D001743:Urinary Bladder / Q000294:innervation*
chemical_list: D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D002211:Capsaicin