Testing Dopamine Neuron Transplants in Rats
Parkinson's disease involves loss of a small population of dopamine generating neurons in the brain. The underlying processes causing this loss happen in all aging brains, but to a greater extent in those who ultimately manifest this condition. One approach to treatment under development is direct replacement of the lost cells, but like many types of cell therapy a lot of work and testing is involved to find the most useful strategies given the cell sources and technologies presently available:
Parkinson's disease is caused, in part, by the death of neurons that release a brain chemical called dopamine, leading to the progressive loss of control over dexterity and the speed of movement. [Researchers have shown] that transplantation of neurons derived from human embryonic stem cells (hESCs) can restore motor function in a rat model of Parkinson's disease, paving the way for the use of cell replacement therapy in human clinical trials.Another approach involving the transplantation of human fetal cells has produced long-lasting clinical benefits; however, the positive effects were only seen in some individuals and can also cause involuntary movements driven by the graft itself. To rigorously assess an alternative hESC-based treatment approach, [scientists] transplanted hESC-derived dopamine neurons into brain regions that control movement in a rat model of Parkinson's disease. The transplanted cells survived the procedure, restored dopamine levels back to normal within five months, and established the correct pattern of long-distance connections in the brain. As a result, this therapy restored normal motor function in the animals. Importantly, the hESC-derived neurons show efficacy and potency similar to fetal neurons when transplanted in the rat model of Parkinson's disease, suggesting that the hESC-based approach may be a viable alternative to the approaches that have already been established with fetal cells in Parkinson's patients.
Link: http://www.sciencedaily.com/releases/2014/11/141106131845.htm