Trials conducted on animals by scientists from Hebrew University in Jerusalem, found that stem cells could be used to rectify brain birth defects by replacing defective cells with stem cells.
Prof. Joseph Yanai and his associates at the Hebrew University-Hadassah Medical School conducted the study.
Neural and behavioural birth defects, such as learning disabilities, are particularly difficult to treat, as compared to defects with known cause factors such as Parkinson's or Alzheimer's disease.
This is because the prenatal teratogen - the substances that cause the abnormalities - act diffusely in the foetal brain, resulting in multiple defects.
But the researchers could overcome this obstacle in laboratory tests with mice by using mouse embryonic neural stem cells. These cells migrate in the brain, search for the deficiency that caused the defect, and then differentiate into becoming the cells needed to repair the damage.
In general, stem cells may develop into any type of cell in the body, however at a certain point they begin to commit to a general function, such as neural stem cells, destined to play a role in the brain/ nervous system.
In the animal model, the researchers were able to reverse learning deficits in the offspring of pregnant mice who were exposed to organophosphate (a pesticide) and heroin. This was done by direct neural stem cell transplantation into the brains of the offspring.
And it was observed that the recovery was almost one hundred percent, as proved in behavioural tests in which the treated animals improved to normal behaviour and learning scores after the transplantation. On the molecular level, brain chemistry of the treated animals was also restored to normal.
Puzzled by the stem cells' ability to work even in those cases where most of them died out in the host brain, the scientists went on to discover that the neural stem cells succeed before they die in inducing the host brain itself to produce large number of stem cells which repair the damage.
Now, the scientists are working towards developing procedures for the least invasive method for administering the neural stem cells, which is probably via blood vessels, thus making the therapy practical and clinically feasible.
The study was presented at the Tel Aviv Stem Cells Conference last spring and will be presented and published next year at the seventh annual meeting of the International Society for Stem Cell Research in Barcelona, Spain.