Lab animals show improved hippocampal spatial memory and fear-conditioning performance post-transplantation
Patients receiving cranial irradiation treatment for brain cancer may find the treatment life-saving, but often suffer progressive and debilitating cognitive detriments, including spatial learning and memory deficits. The cognitive deficits are a contributing factor to the often significant adverse impacts on the surviving patients' quality of life after radiation therapy. In an effort to improve post-irradiation cognitive impairment, scientists at the University of California, Irvine, and colleagues at Neuralstem, Inc. (Rockville, MD), have transplanted fetal stem cells into laboratory animals with radiation-induced cognitive impairments and found that this led to a number of cognitive improvements. The study appears as an early e-publication for the journal Cell Transplantation, and is now freely available on-line at http://www.ingentaconnect.com/content/cog/ct/pre-prints/ct1048acharya.
"Multiple mechanisms contribute to disrupted cognition following irradiation for patients with central nervous system malignancies. These include the depletion of radiosensitive populations of stem and progenitor cells in the hippocampus," said study co-author Dr. Charles L. Limoli of the Department of Radiation Oncology at the University of California, Irvine. "Interventions to combat long-term brain damage resulting from toxic radiation and chemotherapies therapies have yet to be developed. However, stem cell replacement strategies may provide a much needed intervention."
The researchers explored the potential beneficial impact of intra-hippocampal transplantation of fetal-derived human neural stem cells by transplanting the cells into laboratory rats a month after the animals were subjected to cranial irradiation with resulting cognitive deficits. The stem cells were FDA-approved human, fetal-derived neural stem cells provided by Neuralstem, Inc.
"Engrafted stem cells underwent extensive neuronal differentiation, formed new synaptic contacts, released neurotrophic factors, and showed an advanced degree of structural integration into the motor circuitry," reported the research team.