Parkinsons Disease Essays - Neuroscience, Biology, Brain

Parkinson's Disease : Parkinson's disease affects the nerve cells in the brain that produce dopamine. Parkinson's disease symptoms include muscle rigidity ,tremors , and changes in speech and gait. After diagnosis, treatments can help relieve symptoms. Figure SEQ Figure \* ARABIC 3 :Dopamine levels in normal and a pakinson's affected neuron Stem cell therapy in parkinson's disease : Doctors firstly isolated adult stem cells from the patient's brain, they were then cultured in vitro and encouraged to turn into dopamine-producing neurons. As soon as tests showed that the cells were producing dopamine they were then re-injected into the man's brain. After the transplant, the man's condition was seen to improve and he experienced a reduction in the trembling and muscle rigidity associated with the disease. Brain scans taken 3-months after the transplant revealed that dopamine production had increased by 58%, however it later dropped but the Parkinson's symptoms did not return. The study is the first human study to show that stem cell transplants can help to treat Parkinson's. The use of fetal-derived neural stem cells has shown significant promise in rodent models of Parkinson's disease, and the potential for tumorigenicity appears to be minimal. The authors report that undifferentiated human neural stem cells ( hNSCs ) transplanted into severely Parkinsonian 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated primates could survive, migrate, and induce behavioral recovery of Parkinsonian symptoms, which were directly related to reduced dopamine levels in the nigrostriatal system ( 5 ) . Working with these cells, the researchers created dopamine neurons deficient in DJ-1, a gene mutated in an inherited form of Parkinson's. They report that DJ-1-deficient cells -- and especially DJ-1-deficient dopamine neurons -- display heightened sensitivity to oxidative stress, caused by products of oxygen metabolism that react with and damage cellular components like proteins and DNA. In a second paper, they link DJ-1 dysfunct ion to the aggregation of alpha- synuclein , a hallmark of Parkinson's neuropathology. ( 6 , HYPERLINK "http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068820/" \l "b7-ijhs-3-2-0227" 7 ) In summary most of studies using aborted human embryonic tissue indicate that: Clinical benefit does occur; however, the benefit is not marked and there is a delay of many months before the clinical change. Postmortem examinations show that tissue grafts do survive and innervate the striatum. PET scans show that there is an increase in dopamine uptake after transplantation. Follow up studies show that long term benefit does occur with transplantation . ( 8 )