In the late 1980s and over the 1990s, researchers at Lund University in Sweden pioneered the transplantation of new nerve cells into the brains of patients with Parkinson’s disease. The outcomes proved for the first time that transplanted nerve cells can survive and function in the diseased human brain. Some patients showed marked improvement after the transplantation while others showed moderate or no relief of symptoms. A small number of patients suffered unwanted side-effects in the form of involuntary movements.
Ever since the first transplantations were carried out, a fundamental question has been whether the transplanted cells and their neural connections could survive and function over time despite ongoing disease in the patient’s brain. Now researchers at Lund University have proven that transplanted nerve cells can survive for many years and restore normal dopamine production in the transplanted part of the brain. The study has been published by the distinguished scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).
The researchers followed a patient with Parkinson’s disease who underwent transplantation of dopamine-producing nerve cells 24 years before death. The patient showed such marked improvement that medication with L-dopa was no longer necessary three years after the transplantation. Brain-imaging technology allowed the researchers to show that dopamine function was completely normal in the transplanted brain structure ten years after the operation. The new study analyses the patient’s brain and the researchers can now prove that the transplanted dopamine-producing cells and their normal neural connections are still present almost a quarter of a century after the operation.
Wen Li, Elisabet Englund, Håkan Widner, Bengt Mattsson, Danielle van Westen, Jimmy Lätt, Stig Rehncrona, Patrik Brundin, Anders Björklund, Olle Lindvall, Jia-Yi Li. Extensive graft-derived dopaminergic innervation is maintained 24 years after transplantation in the degenerating parkinsonian brain. Proceedings of the National Academy of Sciences, 2016; 201605245 DOI: 10.1073/pnas.1605245113