New Imaging Tool Helps Researchers See Extent of Alzheimer’s Early Damage

Bill Hathaway wrote . . . . . . . . .

New imaging technology allows scientists to see the widespread loss of brain synapses in early stages of Alzheimer’s disease, a finding that one day may help aid in drug development, according to a new Yale University study.

The research, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, compared the density of synapses, which transmit signals between neighboring brain cells, in people with early stages of Alzheimer’s with those of people who have no evidence of the disease. As expected, the loss of synapses in those with an early stage of Alzheimer’s was particularly high in areas surrounding the hippocampus, an area of the brain crucial to formation of memory, the scientists report.

“However, our new methods enable us to detect widespread synaptic losses thoughout the brain,” said Yale’s Adam Mecca, assistant professor of psychiatry and first author of the paper. “This gives us confidence that we may use these results as a biomarker outcome for therapeutic trials, which could help speed development of new drugs to combat the disease.”

To get a clearer picture of the early effects of Alzheimer’s, the researchers used positron emission tomography (PET) imaging of a protein found in almost all brain synapses. Previous imaging technologies had been able to show in broad strokes the loss of brain tissue or reduced brain metabolism in Alzheimer’s. However, the new PET scans show the distribution of synaptic damage, a more specific disease pathology present at early stages of the disease, the authors say.

“These methods will allow us to examine synaptic loss at still earlier stages of disease — when people have evidence of Alzheimer’s pathogenesis but have not yet manifested symptoms,” said Christopher van Dyck, professor of psychiatry, neurology, and neuroscience, and senior author of the study.

Source: Yale University

Researchers Find Our Brains are Powerful, but Secretive

Talor Kubota wrote . . . . . . . . .

When Stanford University neuroscientist Brian Knutson tracked his smartphone usage, he was shocked to learn that he spent twice as much time on his phone as he had anticipated.

Research investigating the neuroscience of choice have found that our brains hold hidden information about the viral potential of online videos. (Image credit: Getty Images)

“In many of our lives, every day, there is often a gap between what we actually do and what we intend to do,” said Knutson, who is a professor of psychology in the School of Humanities and Sciences, reflecting on his smartphone habits. “We want to understand how and why people’s choices lead to unintended consequences – like wasting money or even time – and also whether processes that generate individual choice can tell us something about choices made by large groups of people.”

Toward that end, Knutson and colleagues are investigating an approach he calls “neuroforecasting” – in which they use brain data from individuals who are in the process of making decisions to forecast how larger groups of unrelated people will respond to the same choices. His lab’s latest neuroforecasting work in collaboration with researchers at Stanford’s Graduate School of Business, published Mar. 9 in the journal Proceedings of the National Academy of Sciences, focused on how people spend time watching videos online.

By scanning people’s brains as they selected and watched videos, the researchers discovered that both neural and behavioral responses to a video could forecast how long other people will watch that same video on the internet. When forecasting video popularity on the internet, however, brain responses were the only measure that mattered.

“Here, we have a case where there is information contained in subjects’ brain activity that allows us to forecast the behavior of other, unrelated, people – but it’s not necessarily reflected in their self-reports or behavior,” explained Lester Tong, a graduate student in the Knutson lab. “One of the key takeaways here is that brain activity matters, and can even reveal hidden information.”

Cerebral secrets

The researchers analyzed data from 36 participants, who watched videos while being scanned with a brain imaging technique known as fMRI. The researchers also monitored participants’ behavior – like whether they chose to skip a video – and asked them questions about each video, like how it made them feel and whether they thought it would be popular. Then, they examined how those same videos performed on the internet in terms of daily views and average duration of viewings.

Because videos are complex and change over time, the researchers specifically examined brain responses to the start and end of videos, as well as average responses to each video. They focused on activity in brain regions previously shown to predict peoples’ willingness to spend money.

The researchers found that longer video views were associated with activity in reward-sensitive regions of the brain, while shorter video views were associated with activity in regions sensitive to arousal or punishment. The subjects’ answers to questions about the videos also predicted their own behavior.

When it came to forecasting the behavior of others online, however, the data told a different story. Both the group’s behavior and brain activity forecasted how long people would watch the videos online. However, only group brain activity forecasted the popularity (or views per day) of each video online. During just the first four seconds of watching each video, more activity in the brain region associated with anticipating reward forecasted a video’s popularity online, whereas heightened activity in the region associated with anticipating punishment forecasted decreased popularity.

“If we examine our subjects’ choices to watch the video or even their reported responses to the videos, they don’t tell us about the general response online. Only brain activity seems to forecast a video’s popularity on the internet,” explained Knutson, who co-leads the NeuroChoice Initiative of the Stanford Wu Tsai Neurosciences Institute.

This and related research indicate that some steps of the choice process may prove more useful for broad neuroforecasting than others. By teasing out the specifics of which steps matter, the researchers think neuroforecasting might even apply across groups of different ages, genders, races or cultures when they show similar early neural responses.

Valuable choices

These findings suggest similarities between neuroforecasting how people spend time and how they spend money online, which the team has previously studied in non-traditional markets, including online markets for micro-loans and crowdfunding.

Source: Stanford University

Surgery with Anesthesia not Associated with Indicator of Alzheimer’s Disease

Jay Furst wrote . . . . . . . . .

Older adults who have surgery with general anesthesia may experience a modest acceleration of cognitive decline, even years later. But there’s no evidence of a link to Alzheimer’s disease, according to new research from Mayo Clinic.

The research, published in the British Journal of Anaesthesia, examined brain scans from 585 patients, ages 70 to 91 ― 493 of whom had at least one surgery with general anesthesia. The analysis found cortical thinning in cerebral areas but no significant evidence of deposits of amyloid protein, a hallmark of Alzheimer’s disease. The cortex is the outermost layer of the brain’s nerve cell tissue, and thinning of that tissue is associated with diminished cognitive functions.

“This finding suggests that the modest cortical thinning is not related to Alzheimer’s disease pathology, but is caused by other processes,” says Juraj Sprung, M.D., Ph.D., a Mayo Clinic anesthesiologist and first author of the study. “These results are reassuring and consistent with the conclusion that surgery and anesthesia do not increase the risk for development of Alzheimer’s disease.”

The potential link between surgery with anesthesia and cognitive decline in older adults has been examined for many years, and concerns have grown as animal studies have indicated that exposure to inhaled anesthetics may be related to brain changes similar to those seen with Alzheimer’s disease.

Alzheimer’s disease is a progressive disorder that causes brain cells to degenerate and die. It is the most common cause of dementia and the sixth leading cause of death in the U.S. Also, Alzheimer’s disease causes a continuous decline in cognition and behavior that disrupts a person’s ability to function. While there is no cure, some medications can slow its progression. An estimated 5.8 million Americans are living with the disease, according to the Alzheimer’s Association.

One of the key indicators of Alzheimer’s disease is a buildup of proteins in the cortical area of the brain, which can be visualized by positron emission tomography (PET) scans. The protein deposits, called “amyloid plaques,” have a toxic effect on neurons and can precede any clinical symptoms of the disease by 30 years or more.

The Mayo Clinic study used data from the Mayo Clinic Study of Aging, which started in 2004 and has data on more than 5,000 participants ― all from Olmsted County, Minnesota, where Mayo Clinic in Rochester is located. The study analyzed 585 patients, 493 of whom had at least one surgery with general anesthesia after age 40, and later had PET scans. Of those, the median time between surgery and the PET scan was 25.9 years.

The researchers used two methods to define amyloid deposition in the PET scans. “Regardless of the definition used, no significant associations were detected between exposure to surgery and anesthesia, and increased amyloid deposition,” Dr. Sprung says.

Dr. Sprung and Mayo Clinic colleagues published a study last year that also noted the association between surgical anesthesia and cortical thinning in the signature region for Alzheimer’s disease. The study cautioned that the pathogenesis and mechanisms driving these changes required more study.

The new study concludes that the cortical thinning was not associated with pathologic changes related to Alzheimer’s, but was caused by other undetermined processes.

“Older adults who are considering surgery, and their families, must be properly informed of the risk for slightly accelerated cognitive decline in the years following surgery,” says Dr. Sprung. “However, they should also be made aware that this potential impact may be related to preexisting conditions that necessitate the surgery.”

“Most important, patients should be reassured by our findings that surgery with anesthesia does not lead to changes associated with Alzheimer’s disease,” says Dr. Sprung.

Source: Mayo Clinic


Today’s Comic

Finding the Root to Treat Aging through Dieting

Angel Mendez wrote . . . . . . . . .

Researchers at the University of Minnesota Medical School believe they discovered a new way in which diet influences aging-related diseases.

“Our healthcare as we age is analogous to a tree, and the way we go about it now, when a branch gets diseased, we go to a doctor, and they trim the branch. Then, we go to another doctor, and they trim another branch,” said Doug Mashek, PhD, a professor in the Departments of Medicine and Biochemistry, Molecular Biology and Biophysics. “It’s the roots that we need to be focused on—the common roots of all of these diseases. That’s why we are excited because this pathway has been linked to almost all of them. It’s the roots.”

The root is part of a special diet—one that Dr. Mashek and his team have studied over the last eight years with the help of multiple grants from the National Institutes of Health. Their research findings, recently published in Molecular Cell, focus on the Mediterranean diet. The diet, originally touted by U-famed American physiologist Ancel Keys, emerged during his “Seven Countries Study” when he helped link diet to cardiovascular disease for the first time.

Early studies suggested red wine was a major contributor to the health benefits of the Mediterranean diet because it contains a compound called resveratrol, which activated a certain pathway in cells known to increase lifespan and prevent aging-related diseases. However, work in Dr. Mashek’s lab suggests that it is the fat in olive oil, another component of the Mediterranean diet, that is actually activating this pathway.

“We didn’t start out by studying the Mediterranean diet; we first were focusing on fat,” Dr. Mashek said. “This fat is known to be protective against heart disease and many other aging-related diseases, so by identifying this pathway, it provides a new way of thinking about how consuming olive oil and the Mediterranean diet is actually linked to positive health benefits.”

Yet, merely consuming olive oil is not enough to elicit all of the health benefits. Dr. Mashek’s studies suggest that when coupled with fasting, limiting caloric intake and exercising, the effects of consuming olive oil will be most pronounced.

“We found that the way this fat works is it first has to get stored in microscopic things called lipid droplets, which is how our cells store fat. And then, when the fat is broken down during exercising or fasting, for example, is when the signaling and beneficial effects are realized,” he said.

The next steps for their research are to translate it to humans with the goal of discovering new drugs or to further tailor dietary regimens that improve health, both short-term and long-term.

“We want to understand the biology, and then translate it to humans, hopefully changing the paradigm of healthcare from you going to eight different doctors to treat your eight different disorders,” Dr. Mashek said. “These are all aging-related diseases, so let’s treat aging.”

Source: University of Minnesota

Research Suggests the Start of a “Dietary Revolution” Focused on Alternative Protein

FMCG Gurus have revealed that their research indicates what they call the beginning of a dietary revolution in the US, one focused on alternative protein sources. American consumers, increasingly concerned over their health, are tempted by the increased availability of meat substitutes in fast food outlets amid a mass move away from meat.

The organisation’s consumer research shows that, of those who eat meat regularly, fewer than half say that they have not considered reducing their meat intake. These consumer insights show that there is a move towards meat alternatives and plant-based proteins, even in the diets of those who eat meat. In total, 29% of consumers actively describe themselves as flexitarian.

A significant factor is the increased profile of meat alternatives, and the way that manufacturers are aggressively marketing themselves to capture the meat-eating market. Beyond Meat has risen to a market cap of $7.16B and Impossible Foods was aiming for a $3-5B valuation at the end of 2019. Roughly a tenth of those who are moving away from meat are being tempted by plant-based alternatives, and with recent launches into major fast-food chains like KFC and Subway, that is likely to rise significantly.

It was shown that almost half of those who have reduced their intake suggest that general health concerns are a significant factor with this, with issues about heart health, cancer risks, or digestive health also frequently mentioned. Even without specific concerns, the general perception of meat as a less healthy option leads, by extension, to a level of trust in plant-based products, trust that can be exploited by savvy marketing.

This article is based on data from the FMCG Gurus US Meat and Plant-Based Survey, North American Meat Institute, valuation data from NASDAQ and Food Dive, and information from the Impossible Foods Impact Report 2019.

Source: Vegconomist