Huntington's Just Want to Lay Down

Exercise! Wow the one shot cure

Dr. Kramer’s lecture raved about the benefits of exercise in aging and as a way to help delay and even prevent the onset of mental disorders and cognitive degenerative diseases in some cases. I thought that these finding were amazing and immediately felt the need to get up and get moving, keeping the body healthy to keep the mind well lubricated so to speak. However what really caught my attention was not the benefits that exercise provided but the one exception to this almost perfect treatment. Very briefly Dr. Kramer mentioned that exercise helps virtually everything except for Huntington’s disease. It wasn’t hard to then ask why and what makes Huntington disease so special.

So what is Huntington’s Disease?

            Huntington's disease is caused by a defect on chromosome 4 that causes a part of DNA, called a CAG repeat, to occur many more times than it is supposed to. As individuals with this disease have children the abnormal replicates become increasingly abundant. Normally, this section of DNA is repeated 10 to 28 times but in persons with Huntington's disease, it is repeated 36 to 120 times and with each added replication the chances of developing this disease earlier in live rises. (PubMed 2011) What makes it particularly devastating is the fact that these replicated sequences can seriously mutate and denature proteins and as a result lead to disorders like paranoia, hallucinations, uncontrolled body movements (jerking, twitching and eye spasms) and dementia in some cases.

So how does exercise affect it?

            In a study published in 2010 researchers looked at the effects of exercise on rats with Huntington’s disease, what they found was interesting. They concluded that “exercise impaired motor performance and reduced striatal volume and age of disease onset in a HD mouse model. In addition, total lifespan, progressive weight loss, hyperglycemia, reduced neurogenesis, deficits in immature neuronal morphology; intra-nuclear inclusions, decreased GCL volume and impaired cognitive performance were not changed by exercise.” (Potter et al. 2010) So not only was exercise unable to prevent the onset of HD it actually induced its onset earlier in the rat’s life. A similar study done by Renoir et al. in 2012 looked at the effects of exercise on depressed rats with HD and found similar results, the rats that showed increase activity levels were seen to perform poorly on Morrison’s water maze and also shown increase motor disorders measured by the number of missteps that the rats made.

But why?

I have no idea, it could be a number of things but perhaps the increased metabolism rates of active individuals not only speeds up bodily functions but accelerates abnormal replications of the CAG sequence found in Huntington’s Disease and as a result causes the disease to occur earlier in the organisms life. There isn't a lot of new research that is published yet but I feel in the coming years that this topic might become really hot really fast.   

Work Cited

Board, A.D.A.M. Editorial. "PubMed: Huntington's Disease." Huntington's Disease. U.S. National Library of Medicine, 30 Apr. 2011. Web. 04 Dec. 2013. <http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001775/>.

Potter, Michelle C., Chunyan Yuan, Conwell Ottenritter, Mohamed Mughal, and Henriette Van Praag. "Abstract." National Center for Biotechnology Information. U.S. National Library of Medicine, 07 Dec. 2010. Web. 06 Dec. 2013. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2998194/>.

Renoir, Thibault, Terence YC Pang, Michelle S. Zajac, Grace Chan, Xin Du, Leah Leang, Caroline Chevarin, Laurence Lanfumey, and Anthony J. Hannan. "Treatment of Depressive-like Behaviour in Huntington's Disease Mice by Chronic Sertraline and Exercise." Treatment of Depressive-like Behaviour in Huntington's Disease Mice by Chronic Sertraline and Exercise (2012): n. pag. Mar. 2012. Web. 6 Dec. 2013. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372723/>.