Researchers working with stem cells at the University of Wisconsin-Madison recently made what could be the first steps for curing Huntington’s Disease. The group of researchers found that embryonic stem cells are capable of restoring damaged pathways in the brain caused by the disease (University of Wisconsin-Madison, 2012).
Currently Huntington’s Disease has no cure and those affected suffer from uncontrolled movements, paranoia and a continual decline in cognitive functionality. The severity of the disease is dependent on the number of ‘CAG’ repeats (the sequence of nucleotides that produce the Huntington protein) as seen in figure one. (Medline Plus, 2011).
Figure 1: Graph depicting the number of CAG repeats associated with a ‘Normal/Non-Affected’, ‘Carrier of Huntington’s Disease’ and an ‘Affected person with Huntington’s Disease’. (Prosensa, 2012)
Recently the research team from the University of Wisconsin-Madison have been creating specific brain neurons from embryonic stem cells and testing the ability for stem cells to regenerate and repair the damaged sections of the brain. Thus far it has proved to be promising as mice with Huntington-like conditions have had damaged areas of the brain repaired, restoring motor functions (ScienceNewsLine, March 2012).
Huntington’s Disease interrupts brain activity as a toxic protein called Huntington accumulates in neurons and as a result, disrupts the normal function of these cells. Su-Chun Zhang and his fellow researchers explain how the neurons in the brain called GABA neurons that produce neurotransmitters responsible for communication between the brain and other parts of the body, “Transplanted human GABA neurons reconnect the neural circuitry… Human GABA neuron transplantation corrects motor deficits in Huntington mice” (Cell Stem Cell, 2012). Those affected with Huntington’s are unable to produce the neurotransmitter chemical responsible for communication; hence patients suffer from poor motor skills and uncontrollable movement (ScienceNewsLine, March 2012).
Figure 2: Location of the Basal Ganglia in the human brain
stop functioning effectively and eventually die (Medline Plus, 2011).
As more GABA neurons die more pathways are damaged or destroyed, and consequently the condition of the affected individual worsens. "This circuitry is essential for motor coordination," Zhang says, "and it is what is broken in Huntington patients" (ScienceNewsLine, 2012). The fact that these GABA neurons could repair the pathways and produce the correct neuron transmitter on their own effectively took the research team by surprise.
Baoyang Hu et al., Cell Stem Cell 2011, Human Embryonic Stem Cell-Derived GABA Neurons Correct Locomotion Deficits in Quinolinic Acid-Lesioned Mice, viewed 18th March 2012,
Kevin Sheth et al., U.S. National Library of Medicine 2011, Huntington's disease viewed 18th March,
Prosensa 2002 – 2012, HD – Huntington’s Disease, viewed 18th March,
Science News Line 2012, Stem Cells Hint at Potential Treatment for Huntington's Disease, University of Wisconsin-Madison, viewed 18th March, 2012, <http://www.sciencenewsline.com/biology/2012031517500011.html>
Terry Devitt, University of Wisconsin-Madison 2012, Stem cells hint at potential treatment for Huntington's disease, viewed 18th March 2012,