title: Spinal implants of olfactory ensheathing cells promote axon regeneration and bladder activity after bilateral lumbosacral dorsal rhizotomy in the adult rat.
abstract: OBJECTIVE
  We performed spinal implantation of olfactory ensheathing cells to demonstrate dorsal root afferent regeneration as well as bladder activity restoration after lumbosacral L6 to S2 rhizotomy.
  
  
  METHODS
  Spinal segments receiving bladder innervation, usually L6, S1 and S2, were identified by bipolar stimulation of the ventral roots. Bilateral section of the identified dorsal roots L6 to S2 was performed in 18 male Wistar rats. Immediately after rhizotomy olfactory ensheathing cells or vehicle was unilaterally injected in the vicinity of the sacral parasympathetic nucleus in 9 rats each using a glass micropipette and air pulse system. The severed roots were reattached to the cord with fibrin glue and the animals recovered under antibiotic prophylaxis.
  
  
  RESULTS
  Anatomical regeneration of bladder wall primary afferents was demonstrated by the presence of labeled wheat germ agglutinin-horseradish peroxidase fibers in the dorsal horn and sacral parasympathetic nucleus in 8 of 9 cases of olfactory ensheathing cell implantation but not in the 9 controls injected with vehicle. One week after surgery all rats had an atonic bladder on cystometrography. At 6 weeks 8 of the 9 olfactory ensheathing cell implanted rats had recovered bladder activity. No recovery was observed in controls, in which vehicle was injected instead of olfactory ensheathing cells.
  
  
  CONCLUSIONS
  Regenerated primary afferent fibers from the bladder project to the sacral parasympathetic nucleus, where they presumably form synapses mediating the recovery of bladder activity. Thus, olfactory ensheathing cell implants in the adult rat promote sensory axon regeneration, target reinnervation and bladder activity restoration.
authors.affiliation: Department of Urology and Neuromorphology Laboratory, Biomedical Research Unit, Hospital of Navarra, Pamplona, Spain.
authors.forename: J I
authors.initials: JI
authors.lastname: Pascual
authors.forename: G
authors.initials: G
authors.lastname: Gudiño-Cabrera
authors.forename: R
authors.initials: R
authors.lastname: Insausti
authors.forename: M
authors.initials: M
authors.lastname: Nieto-Sampedro
mesh_terms: D000344:Afferent Pathways; D000818:Animals; D001369:Axons / Q000502:physiology*; D002478:Cells, Cultured; D008297:Male; D009416:Nerve Regeneration; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D019051:Rhizotomy; D013126:Spinal Nerve Roots / Q000502:physiology; D001743:Urinary Bladder / Q000294:innervation*