(Press-News.org) Scientists at the Virginia Tech Carilion Research Institute have discovered how the predominant class of Alzheimer's pharmaceuticals might sharpen the brain's performance
One factor even more important than the size of a television screen is the quality of the signal it displays. Having a life-sized projection of Harry Potter dodging a Bludger in a Quidditch match is of little use if the details are lost to pixilation.
The importance of transmitting clear signals, however, is not relegated to the airwaves. The same creed applies to the electrical impulses navigating a human brain. Now, new research has shown that one of the few drugs approved for the treatment of Alzheimer's disease helps patients by clearing up the signals coming in from the outside world.
The discovery was made by a team of researchers led by Rosalyn Moran, an assistant professor at the Virginia Tech Carilion Research Institute. Her study indicates that cholinesterase inhibitors — a class of drugs that stop the breakdown of the neurotransmitter acetylcholine — allow signals to enter the brain with more precision and less background noise.
"Increasing the levels of acetylcholine appears to turn your fuzzy, old analog TV signal into a shiny, new, high-definition one," said Moran, who holds an appointment as an assistant professor in the Virginia Tech College of Engineering. "And the drug does this in the sensory cortices. These are the workhorses of the brain, the gatekeepers, not the more sophisticated processing regions — such as the prefrontal cortex — where one may have expected the drugs to have their most prominent effect."
Alzheimer's disease affects more than 35 million people worldwide — a number expected to double every 20 years, leading to more than 115 million cases by 2050. Of the five pharmaceuticals approved to treat the disease by the U.S. Food and Drug Administration, four are cholinesterase inhibitors. Although it is clear that the drugs increase the amount of acetylcholine in the brain, why this improves Alzheimer's symptoms has been unknown. If scientists understood the mechanisms and pathways responsible for improvement, they might be able to tailor better drugs to combat the disease, which costs more than $200 billion annually in the United States alone.
In the new study, Moran recruited 13 healthy young adults and gave them doses of galantamine, one of the cholinesterase inhibitors commonly prescribed to Alzheimer's patients. Two electroencephalographs were taken — one with the drugs and one without — as the participants listened to a series of modulating tones while focusing on a simple concentration task.
The researchers were looking for differences in neural activity between the two drug states in response to surprising changes in the sound patterns that the participants were hearing.
The scientists compared the results with computer models built on a Bayesian brain theory, known as the Free Energy Principle, which is a leading theory that describes the basic rules of neuronal communication and explains the creation of complex networks.
The theory hypothesizes that neurons seek to reduce uncertainty, which can be modeled and calculated using free energy molecular dynamics. Connecting tens of thousands of neurons behaving in this manner produces the probability machine that we call a brain.
Moran and her colleagues compiled 10 computer simulations based on the different effects that the drugs could have on the brain. The model that best fit the results revealed that the low-level wheels of the brain early on in the neural networking process were the ones benefitting from the drugs and creating clearer, more precise signals.
"When people take these drugs you can imagine the brain bathed in them," Moran said. "But what we found is that the drugs don't have broad-stroke impacts on brain activity. Instead, they are working very specifically at the cortex's entry points, gating the signals coming into the network in the first place."
The study appears in Wednesday's (May 8) issue of the Journal of Neuroscience in the article, "Free Energy, Precision and Learning: The Role of Cholinergic Neuromodulation."
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News release by Ken Kingery
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A new robotic sensor deployed by Woods Hole Oceanographic Institution (WHOI) in Gulf of Maine coastal waters may transform the way red tides or harmful algal blooms (HABs) are monitored and managed in New England. The instrument was launched at the end of last month, and a second such system will be deployed later this spring.
The results will add critical data to weekly real-time forecasts of New England red tide this year distributed to more than 150 coastal resource and fisheries managers in six states as well as federal agencies such as NOAA, the FDA and the EPA. ...
GAINESVILLE, Fla. — The University of Florida today unveiled the state's most powerful supercomputer, a machine that will help researchers find life-saving drugs, make decades-long weather forecasts and improve armor for troops.
The HiPerGator supercomputer and recent tenfold increase in the size of the university's data pipeline make UF one of the nation's leading public universities in research computing.
"If we expect our researchers to be at the forefront of their fields, we need to make sure they have the most powerful tools available to science, and HiPerGator ...
LA JOLLA, CA---Scientists at the Salk Institute for Biological Studies have identified a protein that drives the formation of pituitary tumors in Cushing's disease, a development that may give clinicians a therapeutic target to treat this potentially life-threatening disorder.
The protein, called TR4 (testicular orphan nuclear receptor 4), is one of the human body's 48 nuclear receptors, a class of proteins found in cells that are responsible for sensing hormones and, in response, regulating the expression of specific genes. Using a genome scan, the Salk team discovered ...
DARIEN, IL – A new study suggests that your level of sleepiness or alertness during the day may be related to the type of food that you eat.
Results show that higher fat consumption was associated with increased objective daytime sleepiness, while higher carbohydrate intake was associated with increased alertness. There was no relationship between protein consumption and sleepiness or alertness. These findings were independent of the subjects' gender, age, and body mass index as well as the total amount of sleep they were getting and their total caloric intake.
"Increased ...
DARIEN, IL – A new study suggests that regularity of bedtime prior to initiation of continuous positive airway pressure (CPAP) therapy is an important factor that may influence treatment compliance in adults with obstructive sleep apnea (OSA).
Results show that bedtime variability was a significant predictor of CPAP adherence, which was defined as four or more hours of treatment use per night. The odds of one-month CPAP non-adherence were 3.7 times greater for every one unit increase in habitual, or pre-treatment, bedtime variability.
"Long-term use of CPAP, such as ...
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Boston (May 7, 2013) – The first successful cornea transplant with donor endothelial tissue preloaded by an eye bank has been performed at Massachusetts Eye and Ear in Boston, Mass. Roberto Pineda II, M.D., Director of the Refractive Surgery Service at Mass. Eye and Ear, and an Associate Professor of Ophthalmology at Harvard Medical School, recently performed the groundbreaking transplant.
Dr. Pineda performed the surgery utilizing donor endothelial tissue that was prepared and pre-loaded into EndoGlide™ (Angiotech Pharmaceuticals, Inc.) cartridges at the Lions Eye Institute ...
WASHINGTON, May 7, 2013 – From New York City's Central Park to Golden Gate Park in San Francisco, America's urban forests store an estimated 708 million tons of carbon, an environmental service with an estimated value of $50 billion, according to a recent U.S. Forest Service study.
Annual net carbon uptake by these trees is estimated at 21 million tons and $1.5 billion in economic benefit.
In the study published recently in the journal Environmental Pollution, Dave Nowak, a research forester with the U.S. Forest Service's Northern Research Station, and his colleagues ...
(PHILADELPHIA) An international group of investigators, led by researchers at Thomas Jefferson University's Kimmel Cancer Center, have solved the mystery of why a substantial percentage of castrate-resistant metastatic prostate cancer cells contain abnormally high levels of the pro-growth protein Stat5. They discovered that the gene that makes the protein is amplified — duplicated many times over — in these cancer cells, which allows them to produce excess amounts of the oncogenic protein.
The study, reported in the May 7 issue of the American Journal of Pathology, found ...
Enzymes could break down cell walls faster – leading to less expensive biofuels for transportation – if two enzyme systems are brought together in an industrial setting, new research by the Energy Department's National Renewable Energy Laboratory suggests.
A paper on the breakthrough, "Fungal Cellulases and Complexed Cellulosomal Enzymes Exhibit Synergistic Mechanisms in Cellulose Deconstruction," appears in the current edition of Energy and Environmental Science. Co-authors include five scientists from NREL and one from the Weizmann Institute in Israel.
The Energy ...
