How Can Embryonic Stem Cells be Used to Treat Patients with Parkinson's disease

Original Paragraph:
People with Parkinson's disease don't have enough dopamine – a chemical that allows messages to be sent to the parts of the brain that control movement. The disease kills dopamine-producing nerve cells, or neurons, in part of the brain called the substantia nigra. Parkinson’s is also linked to formation of clumps of a protein called alpha-synuclein in the brain. These abnormal protein clumps are called Lewy bodies.

Although the underlying cause of Parkinson's disease is unknown, scientists do know which cells and areas of the brain are involved. Researchers are already using stem cells to grow dopamine-producing nerve cells in the lab so that they can study the disease. Because a single, well-defined type of cell is affected, it may also be possible to treat Parkinson’s by replacing the lost nerve cells with healthy new ones.

Key ideas
-People with Parkinson's disease are unable to control movement properly because they do not have enough dopamine, a chemical messenger that allows messages to be sent on parts of the brain that control movement.
-Researchers are using embryonic stem cells to grow dopamine-producing nerve cells, it may be possible to treat Parkinson's by replacing the lost nerve cells with healthy new ones.

Source in MLA:
"Parkinson's Disease: How Could Stem Cells Help?" EuroStemCell. N.p., n.d. Web. 07 Oct. 2014. <http://www.eurostemcell.org/factsheet/parkinson%25E2%2580%2599s-disease-how-could-stem-cells-help>.

Paraphrasing:
People that are suffering from Parkinson's disease are unable to control their movement properly, this is caused by having not enough dopamine that allows messages to be sent to the parts of the brain responsible for movement. The disease causes disability by killing the dopamine-producing nerve cells in the brain. However the causes & mechanisms under this disease is unknown, scientist managed to grow dopamine-producing nerve cells by using embryonic stem cells, which could be potentially used to treat Parkinson's by replacing the lost nerve cells with healthy new ones.

Nerve cells grown in the lab using stem cells

The picture are nerve cells, particularly the dopamine-producing nerve cells that are grown in the lab using embryonic stem cells. They used dyes to label certain areas of the nerve cell, the green dyes are representing the neurons while the red-green chunks are representing the dopamine-producing neurons.