Key to Treating Alzheimer’s: Brain Garbage Truck?

Researchers at the University of Rochester Medical Center point to a newly discovered system, which processes and removes waste in the brain, as a possible key to treating neurological disorders such as Alzheimer’s disease.
Modern scientists are beginning to build on the late-1800s understanding of the “blood-brain barrier” with new incoming knowledge of the brain’s dynamics for removing waste, recently dubbed the glymphatic system. The lymphatic system, a circulatory network of organs and vessels, removes waste materials from the rest of the body, but does not extend to the brain. Scientists began to postulate about how the brain kept house, one of the main issues being that there is no trace of any such system within brain tissue samples. But new technology known as two-photon microscopy allowed scientists to delve deeper into the living brain for study. Coupling the new tech with mice brains, Dr. Maiken Nedergaard, co-director of the URMC for Transitional Medicine, and her colleagues were able to observe and document the extensive waste system of the brain.
The brain is surrounded by a membrane, called the arachnoid, that is flushed with cerebral spinal fluid (CSF) which flows through the brain on the same pathways as the arteries reaching the brain. CSF is drawn into the brain tissue through a system of conduits controlled by glia, support cells. CSF is moved through the brain at high speeds, picking up excess proteins and waste products along the way. The fluid and waste are channeled into a system which parallels veins and transports the byproducts from the brain, down the spinal column, and to the liver where everything is ultimately broken down. With this discovery, scientists can delve into the research regarding how to apply this knowledge in the treatment of neurological disorders. This find may prove especially beneficial in the case of Alzheimer’s, a disease whose hallmark is the build-up of beta amyloid plaques. Further research would test whether manipulating glia to ramp up waste removal would better prevent the build-up of excess proteins such as beta amyloid.
Source:
1) University of Rochester Medical Center (2013, June 27). Brain’s ‘garbage truck’ may hold key to treating Alzheimer’s and other disorders. ScienceDaily. Retrieved July 1, 2013, from http://www.sciencedaily.com/releases/2013/06/130627142402.htm

By Lauren Horne

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Antidepressant May Slow Progression of Alzheimer’s Disease

According to research by the Washington University School of Medicine, published in Science Translational Medicine, a common antidepressant can reduce the production of brain plaques.

 

Brain plaques correlate closely with memory problems and other cognitive impairments caused by Alzheimer’s disease. Stopping plaque buildup is believed to help halt the mental decline of Alzheimer’s patients. Scientists found the antidepressant citalopram stopped the growth of plaques in a mouse model of the disease. The research also found, in young adult humans who were cognitively healthy, that a single dose of the antidepressant lowered production of amyloid beta by thirty-seven percent. The researchers stress that while the results may be promising, any treatment at this point is premature.

 

Levels of amyloid beta, a protein produced by normal brain activity, rise in the brains of patients with Alzheimer’s, and eventually clump together to form plaques. Most antidepressants keep serotonin circulating in the brain, and this study was born from the theory that serotonin helps reduce plaque levels in cognitively health individuals.

 

For this research, scientists gave citalopram to older mice with brain plaques. They used two-photon imaging to track the growth of plaques in the mice for twenty-eight days. The results showed a rate of formation of new plaques decreased by seventy-eight percent. In a second experiment, the scientists gave citalopram to twenty-three people cognitively healthy people aged eighteen to fifty. Spinal fluid from the participants over the next day showed a thirty-seven percent drop in amyloid beta production.

 

Sources:

  1. Sheline YI, West T, Yarasheski K, Swarm R, Jasielec MS, Fisher JR, Ficker WD, Yan P, Xiong C, Frederiksen C, Grzelak MV, Chott R, Bateman RJ, Morris JC, Mintun MA, Lee J-M, Cirrito JR. An antidepressant decreases CSF Ab production in healthy individuals and in transgenic AD mice. Science Translational Medicine, online May 14, 2014.
  2. Washington University in St. Louis. (2014, May 14). Antidepressant may slow Alzheimer’s disease. ScienceDaily. Retrieved May 16, 2014 from sciencedaily.com/releases/2014/05/140514142326.htm

By Emma Henson

The Roskamp Institute is a 501(c)3 research facility dedicated to translating the efforts of its qualified research staff into real-world results for those suffering from neurological diseases. To learn more about our programs and to get information about donating, visit www.rfdn.org.