Due to degenerative diseases such as stroke and Parkinson's disease, it is difficult to repair after injury. The unlimited adaptability of stem cells provides hope for better nerve repair. However, the complexity of precise brain coordination hinders the development of clinical therapies. In a new study of these diseases, researchers at the University of Wisconsin-Madison demonstrated a proof-of-concept stem cell therapy in a mouse model of Parkinson's disease. They found that stem cell-derived neurons can integrate well into the correct areas of the brain, connect with natural neurons and restore motor function.
The key is identity. By carefully tracking the fate of transplanted stem cells, scientists discovered that the identity of these cells (in the case of Parkinson's disease, the cells that produce dopamine) determines their connection and function. Scientists say this study shows that neural stem cell therapy is a realistic goal, because more and more methods can generate dozens of unique neurons from stem cells. However, more research is needed to translate the findings from mice into humans. The UW-A research team led by Madison neuroscientist Zhang Suchun published the findings in the journal CellStemCell. The research was led by post-doctoral researchers in Zhang's laboratory, who are currently teachers in China and Singapore, Chen Yuejun, Zion Mann and Tao Yechen.
Our brains are precisely connected by specific nerve cells in specific locations, so they can participate in all complex behaviors. Professor Ming Zhang of Neuroscience said: “Everything depends on the circuits associated with specific cell types. .. Department of Neurology, University of Wisconsin-Madison, Wisman Center. "Nerve damage usually affects specific brain areas or specific cells. Type and destroy the circuit. To treat these diseases, these circuits must be repaired. "
Parkinson's Disease In order to repair these circuits in a mouse model of human embryonic stem cells, the researchers first distinguished dopaminergic neurons that would die of Coax Parkinson's disease. They transplanted these new neurons into the midbrain of mice, which is the brain area most affected by Parkinson's disease. After a few months, the mice have time to integrate new neurons into the brain and show better exercise capabilities. After careful inspection, Zhang's team was able to confirm that the transplanted neurons were connected to the motor control areas of the brain over long distances. Nerve cells also establish contact with the regulatory areas of the brain that enter new neurons and prevent them from being overstimulated.
The feed-in and feed-out connections of the two groups of transplanted neurons are similar to the circuits established by natural neurons. This only applies to dopamine-producing cells. Similar experiments with cells that produce the neurotransmitter glutamate did not help the repair of Parkinson's disease, but did not repair the motor circuit, which revealed the importance of neuronal identity in repairing damage.