Mature brains are not good at repairing themselves after trauma, stroke, or degenerative diseases such as Parkinson's disease. Stem cells with unlimited adaptability provide hope for better nerve repair. The researchers demonstrated a proof of concept of stem cell therapy in a mouse model of Parkinson's disease. They found that neurons from stem cells can integrate well into the correct areas of the brain, connect with native neurons and restore motor function in mice.
Our brain precisely connects special nerve cells at specific locations, so we can participate in all complex behaviors. It all depends on the circuits connected by the specific cell type. Nerve damage usually affects specific brain areas or specific cell types, thereby destroying electrical circuits. In order to treat these diseases, we must restore these circuits.
In order to repair these circuits in a mouse model of Parkinson's disease, the researchers first induced human embryonic stem cells to differentiate into dopamine-producing neurons, which die seriously in Parkinson's disease. They transplanted new neurons into the midbrain of mice, which is most affected by Parkinson's disease. A few months later, when the new neurons had time to integrate into the brain, the mice's motor skills improved.
In order to finally confirm that the transplanted neurons repaired the damaged circuit in Parkinson's disease, the researchers inserted a gene switch in the stem cells. When the cells are exposed to special drugs or injected drugs in the diet, these switches will increase or decrease the activity of the cells. When these stem cells were turned off, the mice’s improvement in exercise disappeared, indicating that stem cells are essential for restoring Parkinson’s damaged brain. Every neurological disease or injury requires its own special nerve cells to treat, but the treatment plan may be similar. Researchers use Parkinson's disease as a model, but the principles should be the same for many different neurological diseases.