ROCKVILLE, Md., Aug. 1, 2013 /PRNewswire/ -- Neuralstem, Inc. (NYSE MKT: CUR) announced that a paper published in the journal "Cell Transplantation - The Regenerative Medicine Journal," reported that Neuralstem's spinal cord-derived human neural stem cells, NSI-566, improved cognitive function in rats who'd received radiation to the brain, as assessed by two separate cognitive tasks ( http://www.ingentaconnect.com/content/cog/ct/pre-prints/ct1048acharya ). In the paper, "Transplantation of Human Fetal-Derived Neural Stem Cells Improves Cognitive Function Following Cranial Irradiation," researchers at the University of California Irvine showed that rats who received NSI-566 transplants after brain irradiation improved hippocampal spatial memory as well as contextual fear conditioning performance, a brain function that relies on intact amygdala function. Both the amygdala and the hippocampus are parts of the brain involved with memory formation. (Logo: http://photos.prnewswire.com/prnh/20061221/DCTH007LOGO ) The transplanted cells developed into a significant number of new neurons in the hippocampus, as well as a smaller portion of glial subtypes. There was no evidence of teratoma, or tumor growth, in these cells. Radiation after tumor-removal surgery is a common therapy in the treatment of brain cancer in humans, but can result in significant cognitive defects. "We are broadening our neural stem cell therapy programs from treating motor deficits to treating cognitive deficits, which involve two distinct anatomical circuits, pathogenic mechanisms, and treatment strategies," said Karl Johe PhD, Neuralstem Chairman and Chief Scientific Officer. "In this published study, our collaborators at the University of California, Irvine have demonstrated proof-of-principle for ameliorating cognitive dysfunction when the cells were injected two days after irradiation, a model that is similar to a potential clinical intervention given to treat brain cancer patients. Such irradiation frequently leads to serious and debilitating cognitive loss in patients, ranging from pediatric patients afflicted with medulloblastoma, to adults with glioblastoma multiforme. No current solutions exist to treat this unmet medical condition. We believe that the key therapeutic mode of action by the transplanted cells in this model is to protect and preserve neurogenesis in the hippocampus. In clinical translation, this suggests early intervention with Neuralstem cells could prevent cognitive complications due to an irradiation therapy." About the Study 29 rats were divided into three groups. The first group received no cranial radiation after sham brain surgery. The second got the surgery and radiation alone. The third group got surgery, radiation, and were transplanted with NSI-566 neural stem cells one month post surgery.