Transplanting small numbers of nerve cells directly into the brain has restored the learning ability of brain-damaged rats — and might be able to defeat the memory loss of Alzheimer's disease.
Scientists in India have been researching transplanting parts of the nervous system in order to help sufferers of Alzheimer's Disease. By replicating the disease's effects in rats, they've found that transplanting nerve-cells brings back the animals' ability to learn.
The researchers at India's National Institute for Mental Health and Neuro Sciences and National Centre for Biological Sciences first damaged the subiculum of the rats brain, which lead to the deterioration of the hippocampus. The shrinkage of the hippocampus during Alzheimer's disease is thought to lead to the loss of memory and learning, the most visible of disease's effects.
Once the rats had been brought to this Alzheimers-like state, the researchers took cultured lines of hippocampal cells — taken from newborn transgenic rats and cultured — and precisely injected them into the hippocampi of half the rodents. After two months, both batches of rats were run through standardized mazes. The rats that had received the injections were back to pre-damage levels of learning and recall, while those that hadn't received the transplants struggled to learn the course.
What seems to have happened is that the transplanted cells settled in an area of the hippocampus called the dentate gyrus, where they proceeded to help pump out growth factors which create an environment were neurons can grow. There was a threefold increase in neurotrophic and fibroblastic growth factor, which allowed the hippocampus to regenerate from the inflicted damage, and restored the rat's abilities to learn and remember to the level of un-damaged rats.
The implications of this research are astounding for sufferers of neurodegenerative diseases. This study is specifically designed as a precursor to further work with Alzheimer's, but altering the brain to create an environment where it can succeed in regenerating damaged components is a fascinating concept. These seedling transplants could revolutionize the way we look at repairing the brain, for a disease that effects millions.