title: Transplantation of stem cells from the adult human brain to the adult rat brain.
abstract: OBJECTIVE
  To investigate the migration, proliferation, and differentiation of stem cells and neural progenitor cells (NPCs) from the adult human brain after transplantation into adult rodent brains.
  
  
  METHODS
  Adult human NPCs were obtained from temporal lobe specimens removed because of medical intractable epilepsy. The cells were transplanted into the posterior periventricular region above the hippocampus in the brains of either healthy adult rats (control) or rats with selective injury of the hippocampal CA1 region (global ischemia).
  
  
  RESULTS
  In the control animals, grafted cells were mainly distributed from the site of transplantation toward the midline along white matter tracts. The density of transplanted cells elsewhere, including the hippocampus, was low and apparently random. In animals with CA1 damage, NPCs showed targeted migration into the injured area. Cell survival at 10 weeks was 4.7 +/- 0.3% (control, n = 3) and 3.7 +/- 1.1% (ischemia, n = 3); at 16 weeks, cell survival was 3.4 +/- 0.6% (control, n = 2) and 7.2 +/- 1.5% (ischemia, n = 2), i.e., comparable to what has been observed earlier when transplanting embryonic tissue into the human brain or progenitor cells between inbred rats. The number of dividing cells decreased with time. Sixteen weeks after transplantation, 4 +/- 1% (n = 4) of the cells showed proliferative activity. We did not observe signs of tumor formation or aberrant cell morphology. Neuronal differentiation was much slower than what has been observed earlier in vitro or after transplantation to the developing nervous system, and 16 weeks after transplantation many surviving cells were still in maturation.
  
  
  CONCLUSIONS
  The present study shows that adult human NPCs survive, show targeted migration, proliferate, and differentiate after grafting into the adult rat brain.
authors.affiliation: Vilhelm Magnus Center, Institute for Surgical Research, and Department of Neurosurgery, Ullevål University Hospital and Rikshospitalet, University of Oslo, Norway. havard.olstorn@medisin.uio.no
authors.forename: Havard
authors.initials: H
authors.lastname: Olstorn
authors.forename: Morten C
authors.initials: MC
authors.lastname: Moe
authors.forename: Geir K
authors.initials: GK
authors.lastname: Røste
authors.forename: Tjerk
authors.initials: T
authors.lastname: Bueters
authors.forename: Iver A
authors.initials: IA
authors.lastname: Langmoen
mesh_terms: D000328:Adult; D000818:Animals; D002545:Brain Ischemia / Q000628:therapy*; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D006801:Humans; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology*; D014183:Transplantation, Heterologous