Over 30,000 people in the United States are diagnosed with Huntington’s disease, which is characterized by uncontrollable muscle spasms. This debilitating congenital neurological disorder has no treatment, and over time takes away muscle coordination and cognitive abilities of the patient. However, new stem cell research using stem cells may give hope to those with the disease.
The cause of Huntington’s disease can be found in GABA neuron cells, which produce a chemical neurotransmitter responsible for the communication network in the brain that coordinates movement. In Huntington’s patients, the GABA neuron cells degrade, causing a disruption in key neural circuitry, and resulting in the loss of motor function.
Neuroscientist Su-Chun Zhang, of the University of Wisconsin-Madison specializes in making various types of brain cells from human embryonic cells. A recent research study co-authored by Zhang used large amounts of GABA neurons made from human embryonic stem cells. The research goal was to see if these cells could integrate into the brain of a mouse with Huntington’s-like symptoms.
The success of the trial went much further than this, and to the surprise of Zhang and his colleagues, the cells not only integrated, but projected to the proper target and reestablished the broken communication network. The result was restoration of the motor function in the mouse.
“This circuitry is essential for motor coordination, and it is what is broken in Huntington patients. The GABA neurons exert their influence at a distance through this circuit. Their cell targets are far away,” explained Zhang. “Many in the field feel that successful cell transplants would be impossible because it would require rebuilding the circuitry. But what we’ve shown is that the GABA neurons can remake the circuitry and produce the right neurotransmitter.”
Neuroscientists typically considered the adult brain to be very stable, but this research shows that the adult brain may be more malleable than originally thought. For patients with Huntington’s, which has no effective treatment, this is exciting news. However, Zhang stresses that the research, while promising, will take quite some time to test and perfect in humans.