Fecal implants drive behavioral and cognitive changes in Alzheimer’s model

Gut microbiome could be path toward treating or forestalling cognitive decline

February 8, 2022

Science Daily/Oregon Health & Science University

New research in mice for the first time draws a definitive causal connection between changes in the gut microbiome to behavioral and cognitive changes in an animal model of Alzheimer's disease.

The study, published today in the journal Frontiers in Behavioral Neuroscience, suggests new avenues involving the use of probiotics to treat and potentially forestall symptoms of dementia associated with neurodegenerative diseases including Alzheimer's.

The research was led by scientists at Oregon Health & Science University.

"We found that modulating the gut microbiome by fecal implants in germ-free mice induces behavioral and cognitive changes in an Alzheimer's disease model," said senior author Jacob Raber, Ph.D., professor of behavioral neuroscience in the OHSU School of Medicine. "To the best of my knowledge, no one has shown that before in an Alzheimer's disease model."

The work follows on a previous OHSU study in mice, published last year, that revealed a correlation between the composition of the gut microbiome and the behavioral and cognitive performance of mice carrying genes associated with Alzheimer's.

In the new study, researchers carefully manipulated the digestive tract of mice using fecal implants.

They found changes in measures of behavior and cognition among three different genotypes and between males and females. Two of the genotypes involved mirror those associated with a predisposition to Alzheimer's in people.

Researchers found that changes in the gut microbiome clearly affected behavioral and cognitive changes measured in mice.

The study suggests possible avenues for forestalling dementia through targeted use of probiotics or fecal transplants, which already have been used to manipulate the gut microbiome in people. However, Raber said much more research needs to be conducted to ascertain the mechanism of these behavioral and cognitive effects, because the relationship between these effects and gut microbiome is influenced by genotype and sex.

"People can buy probiotics over the counter, but we want to make sure the right treatment is being used for each patient, and that it actually benefits them," Raber said. "The gut microbiome is a complex environment. If you change one element, you'll also change other elements, so you want to make sure to select a probiotic that promotes brain health and brain function for each patient, while limiting any negative side effects."

https://www.sciencedaily.com/releases/2022/02/220208124437.htm

Greater body fat a risk factor for reduced thinking and memory ability

February 1, 2022

Science Daily/McMaster University

A new study has found that greater body fat is a risk factor for reduced cognitive function, such as processing speed, in adults.

Even when the researchers took cardiovascular risk factors (such as diabetes or high blood pressure) or vascular brain injury into account, the association between body fat and lower cognitive scores remained. This suggests other not yet confirmed pathways that linked excess body fat to reduced cognitive function.

In the study, 9,166 participants were measured by bioelectrical impedance analysis to assess their total body fat.

As well, 6,733 of the participants underwent magnetic resonance imaging (MRI) to measure abdominal fat packed around the organs known as visceral fat, and the MRI also assessed vascular brain injury -- areas in the brain affected by reduced blood flow to the brain.

The results were published today in JAMA Network Open.

"Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function," said lead author Sonia Anand, a professor of medicine of McMaster University's Michael G. DeGroote School of Medicine and a vascular medicine specialist at Hamilton Health Sciences (HHS). She is also a senior scientist of the Population Health Research Institute of McMaster and HHS.

She added that "the effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function."

Co-author Eric Smith, a neurologist, scientist and an associate professor of clinical neurosciences at the University of Calgary, said that "preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage."

Smith is head of the brain core lab for the two population cohorts used for this new analysis- the Canadian Alliance for Healthy Hearts and Minds (CAHHM) and PURE Mind- a sub-study of the large, international Prospective Urban Rural Epidemiological (PURE) study.

The participants were in the age range of 30 to 75 with an average age of about 58. Just over 56% were women; they all lived in either Canada or Poland. The majority were White European origin, with about 16% other ethnic backgrounds. Individuals with known cardiovascular disease were excluded.

https://www.sciencedaily.com/releases/2022/02/220201144019.htm

People with less memory loss in old age gain more knowledge

New findings on cognitive development in adulthood

February 3, 2022

Science Daily/Max Planck Institute for Human Development

Do cognitive abilities change together, or do they change independently of each other? An international research team from the USA, Sweden, and Germany involving the Max Planck Institute for Human Development has presented new findings now published in Science Advances.

At the age of 20, people usually find it easier to learn something new than at the age of 70. People aged 70, however, typically know more about the world than those aged 20. In lifespan psychology this is known as the difference between "fluid" and "crystallized" cognitive abilities. Fluid abilities primarily capture individual differences in brain integrity at the time of measurement, whereas crystallized abilities primarily capture individual differences in accumulated knowledge.

Accordingly, fluid and crystallized abilities differ in their average age trajectories. Fluid abilities like memory already start to decline in middle adulthood. In contrast. crystallized abilities such as vocabulary show increases until later adulthood and only evince decline in advanced old age.

This divergence in the average trajectories of fluid and crystallized abilities has led to the assumption that people can compensate for fluid losses with crystallized gains. For instance, if an individual's memory declines, this loss, it is assumed, can be compensated for by an increase in knowledge.

A study of a research team from Germany, Sweden and the USA now shows that this compensation hypothesis has more limits than previously claimed. The researchers analyzed data from two longitudinal studies, the Virginia Cognitive Aging Project (VCAP) study from the USA and the Betula study from Sweden. In the VCAP study, 3633 female and 1933 male participants aged 18-99 years at the first occasion of measurement were followed for a period of up to 18 years and assessed up to eight times. The Betula study involved 1803 women and 1517 men who were between 25 and 95 years old at the first measurement occasion and examined up to four times over 18 years.

The research team used multivariate methods of change measurement to examine the extent to which individual differences in changes in crystallized abilities are related to individual differences in fluid changes. The findings are clear: The correlations between the two types of changes observed in both studies were very high. Thus, individual differences in cognitive development are, to a large extent, domain-general and do not follow the fluid-crystallized divide. What this means is that individuals who show greater losses in fluid abilities simultaneously show smaller gains in crystallized abilities, and persons whose fluid abilities hardly decline show large gains in crystallized abilities.

These findings are in accordance with the everyday observation that some people remain mentally fit in many areas into very old age while others' cognitive functioning declines across the board.

"In intelligence research, people often talk about a general factor or g-factor of intelligence that expresses the commonality of different cognitive abilities," says the lead author of the study, Elliot Tucker-Drob of the Department of Psychology and the Population Research Center at the University of Texas at Austin, USA. "In previous work, we have already demonstrated that not only individual differences in cognitive abilities at a given point in time can be captured by a general factor, but also changes of cognitive abilities. Our new results confirm this finding and demonstrate that changes in crystallized abilities can indeed be subsumed under a general factor of common change."

"Our findings call for a revision of textbook knowledge," adds Ulman Lindenberger, Director of the Center for Lifespan Psychology at the Max Planck Institute for Human Development in Berlin. "If those who show the largest fluid losses also show the smallest crystallized gains, then this places tighter limits on the compensatory power of knowledge than previously believed." For example, people whose memory is declining, also show a low gain in knowledge, even though they are in most need of such gains. Conversely, individuals with small fluid losses and strong crystallized gains are less likely to be in need of relying on compensatory processes to begin with.

Overall, the results underscore the great importance of identifying and supporting modifiable influences that contribute to the general maintenance of cognitive abilities in later adulthood and old age. An example is physical exercise that can prevent cardiovascular diseases and thereby help to maintain cognitive abilities.

https://www.sciencedaily.com/releases/2022/02/220203103001.htm

Do we get our most creative ideas when walking?

January 14, 2022

Science Daily/University of Würzburg

Movement helps us to think creatively. This insight is over 2000 years old -- and already known to the philosophers in ancient Greece.

However, what is the connection between movement and cognition from a scientific point of view? What happens in the brain when we walk? Are people who rarely move less creative?

"Our research shows that it is not movement per se that helps us to think more flexibly," says neuroscientist Dr Barbara Händel from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany. Instead, the freedom to make self-determined movements is responsible for it.

Accordingly, even small movements while sitting can have the same positive effects on creative thinking. However, the researcher does not derive any concrete movement suggestions from her work: "The important thing is the freedom to move without external constraints."

Don't stare at small screens for too long

It is important, she says, that movement is not suppressed or forced into regular patterns. "Unfortunately, this happens when people focus for example on a small screen," explains the JMU researcher.

The increased use of mobile phones and similar devices -- also in the field of education at the time of the Corona pandemic -- could therefore have a negative effect on cognitive processes such as creativity.

The experiments that Barbara Händel and her doctoral student Supriya Murali conducted are described in detail in a recent publication in the journal Psychological Research.

Background

How do people perceive their environment? What effect do sensory stimuli have in the peripheral nervous system and what in the brain? What influence do body movements have on perception of sensory input? Researchers like Barbara Händel are interested in such questions for many reasons. In the long term, their findings could contribute to a better understanding of diseases that affect body movements as well as cognitive processes.

https://www.sciencedaily.com/releases/2022/01/220114115643.htm

Brain function boosted by daily physical activity in middle-aged, older adults

January 31, 2022

Science Daily/University of California - San Diego

A new study by researchers at University of California San Diego School of Medicine adds to the canon of research associating physical activity with cognitive performance, this time using 90 middle-aged and older subjects who wore accelerometers while physically active and completed mobile cognitive testing from home.

"The future of lifestyle interventions really needs to be remote-based," said Raeanne Moore, PhD, associate professor in the Department of Psychiatry at UC San Diego School of Medicine and principal investigator of the study. "The pandemic has made this especially clear."

On the days their physical activity increased, the study found, the 50- to 74-year-old participants performed more effectively on an executive function task, and on the days when their physical activity decreased, so too did their cognitive performance.

The findings published Jan. 31, 2022 in the journal JMIR mHealth and uHealth.

"It was a very linear relationship," Moore said. "We hypothesized that we would find this, but we couldn't be sure because we weren't telling people to increase their physical activity. They just did what they do every day."

First author Zvinka Zlatar, PhD, a clinical psychologist at UC San Diego School of Medicine, added: "Future interventions, in which we ask people to increase their physical activity, will help us determine if daily changes in physical activity lead to daily gains in cognition measured remotely or vice versa."

The correlation between physical activity and cognition remained when adjustments were made for various co-morbidities, such as HIV status, age, sex, education and race/ethnicity. But it held only for persons who function dependently -- who rely on others to perform the tasks of daily living, such as managing household activities or paying the bills.

"For them, physical activity may have a greater benefit on daily, real-world cognitive performance," Moore said, a finding consistent with research into Alzheimer's disease and related dementias.

Though it didn't fall within the purview of this study, Moore speculated that, because functionally independent adults likely perform more cognitively stimulating and social activities, which are known to have positive impacts on brain health, physical activity may have less of an impact on cognition.

Moore and Zlatar said their work has implications for the development of novel digital health interventions to preserve brain health in aging.

"We don't know yet if there's a cumulative, long-term effect to these small daily fluctuations in cognition," Zlatar said. "That's something we plan to study next -- to see if performing physical activity at different intensities over time, in unsupervised settings, can produce long-term improvements in brain health and sustained behavior change."

https://www.sciencedaily.com/releases/2022/01/220131164208.htm

Change of heart? It may affect thinking and memory skills in middle age

January 26, 2022

Science Daily/American Academy of Neurology

Subtle changes in the structure and the diastolic function of a person's heart between early adulthood and middle age may be associated with a decline in thinking and memory skills. The research is published in the January 26, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology. The diastolic function of the heart is when it rests between beats and the chambers fill with blood.

"Cardiovascular risk factors such as high blood pressure, high cholesterol and diabetes have been associated with an increased risk for cognitive impairment, but much less is known about heart structure and function and the risks for cognition," said study author Laure Rouch, PharmD, PhD, of the University of California, San Francisco. "We followed young adults for 25 years into middle age and found declines in thinking and memory skills independent of these other risk factors. Our findings are of critical importance in the context of identifying potential early markers in the heart of increased risk for later-life cognitive decline. Such abnormalities are common and often underdiagnosed as they do not produce any obvious symptoms."

The study looked at 2,653 people with an average age of 30. Participants had echocardiograms, ultrasound images of the heart, at the start of the study and again 20 and 25 years later. Echocardiograms are non-invasive and widely available.

Researchers used the images to measure the following: the weight of the left ventricle, one of four chambers of the heart; the volume of the blood that filled the left ventricle when pumping; and how well the left ventricle pumped blood to the body, specifically the percentage of blood pumped out of the heart.

Researchers found over 25 years, there was an average increase in the weight of the left ventricle of 0.27 grams per square meter per year (g/m2), with average weight of 81 g/m2 in the first year and 86 g/m2 in the last year. There was also an average increase in left atrial volume of 0.42 milliliters of blood per square meter (mL/m2) with average volume of 16 mL/m2 in the first year and 26 mL/m2 in the last year.

In the last year of the study, participants were given six cognitive tests to measure thinking and memory skills including global cognition, processing speed, executive function, delayed verbal memory and verbal fluency. Tests included tasks like recalling words from a list 10 minutes after looking at the list, as well as substituting symbols for numbers using a key at the top of the page.

After adjusting for factors like age, sex and education, researchers found that a greater than average increase from early to middle adulthood in the weight of a person's left ventricle was associated with lower midlife cognition on most tests.

Tests included a common dementia test that asks participants to do tasks like draw lines connecting alternating letters and numbers, and repeat five words, complete other tasks, and then repeat the same five words. Scores range from zero to 30 with 26 and higher representing normal cognition. Participants with a greater than average midlife increase in left ventricle weight had an average score of 22.7 while those without a greater than average increase in weight had an average score of 24.

Researchers also found a greater than average increase from early to middle adulthood in left atrial volume was associated with lower midlife global cognition.

However, a greater than average decrease in the percentage of blood pumped out of the left ventricle was not associated with cognition.

"What is interesting is that our results were similar after adjusting for cardiovascular risk factors such as high blood pressure, diabetes, smoking and obesity," Rouch said. "As early as young adulthood, even before the occurrence of cardiovascular disease, there may be heart abnormalities that could be risk markers for lower thinking and memory skills in middle age. In the future, a single echocardiogram may help identify people at higher risk of cognitive impairment."

Rouch said that future research should determine whether interventions to improve the structure and function of the heart could benefit brain health. She said, "The question of whether altered cardiac structure and function could be a risk factor for cognitive impairment has major public health implications and could reveal another important heart-brain connection."

A limitation of the study is echocardiograms were performed up to 25 years apart using slightly different procedures and equipment, which may make the data hard to compare.

https://www.sciencedaily.com/releases/2022/01/220126165518.htm

Study now links non-mutated Apolipoprotein E to dementia in the aging brain

January 26, 2022

Science Daily/Elsevier

Researchers exploring dementia-related proteins in the brain identified Apolipoprotein E (ApoE) as a key misfolded protein. About 25% of individuals, and 50% of individuals with Alzheimer disease, have a genetic mutation, the APOE ε4 allele -- a known risk factor for the disease. The researchers were surprised to find that even in the brains of patients without the disease-driving APOE ε4 allele, ApoE proteins were strongly enriched in dementia. Their findings appear in The American Journal of Pathology, published by Elsevier.

"Dementia is very complex, but you can simplify it: the disease is caused by 'gloppy proteins' in the brain," explained lead investigator Peter T. Nelson, MD, PhD, Sanders-Brown Center on Aging and Department of Pathology, University of Kentucky, Lexington, KY, USA. "I'm not making light of it -- these 'sticky' misfolded proteins often end up destroying the brain, the mind, the memories and everything else for millions of people who suffer from dementia. We want to understand specifically which proteins are the problem."

The investigators used mass spectrometry to characterize the complete set of proteins, or proteome, from the amygdalae of 40 participants from the University of Kentucky Alzheimer's Disease Center autopsy cohort. The amygdala is vulnerable to mis-aggregated proteins associated with dementia and is often affected even at the earliest stages of disease. The subjects ranged from cognitively normal to severe amnestic dementia. Although previous studies have examined the human amygdala proteome, none have reported on a sample of this size with dementia subjects and control subjects for comparison.

As anticipated, portions of proteins previously associated with neurodegenerative diseases were found in the brains of patients with dementia, including proteins called Tau (associated with neurofibrillary tangles), Aβ (associated with amyloid plaques), and α-Synuclein (associated with Lewy Body disease). Aβ and α-Synuclein correlated strongly with clinical diagnosis of dementia. Tau and Aβ proteins, but not α-Synuclein, were occasionally detectible in cognitively normal subjects and those with mild cognitive impairment. Overall, Dr. Nelson observes, the findings for these proteins were in line with expectations.

The data also revealed a close correlation between dementia diagnosis and the detection of ApoE peptides in the brain. The correlation with dementia for ApoE was even stronger than that seen for Tau, Aβ, or α-Synuclein. Moreover, the ApoE peptides were significantly enriched even in dementia patients who lack the APOE ε4allele. The results emphasize the relevance of the ApoE protein as an aberrantly aggregated protein in its own right, rather than just an "upstream" genetic risk factor.

"Our study adds to an evolving appreciation of multiple misfolded proteins in the human brain and moves the field forward by emphasizing that ApoE may be a stong contributor to the dementia prototype, even in individuals who do not have the disease-driving version of the APOE gene," said Dr. Nelson. "Even in persons lacking the APOE ε4 allele, ApoE may indeed be among the most impactful 'gloppy proteins' in aging brains."

https://www.sciencedaily.com/releases/2022/01/220126122408.htm

Seeing the same GP improves treatment for people with dementia

January 24, 2022

Science Daily/University of Exeter

People with dementia who see the same GP each time have lower rates of health complications and fewer emergency hospital admissions, according to a new study.

The research, led by the University of Exeter and published in the British Journal of General Practice (BJGP) analysed more than 9,000patient records of people diagnosed with dementia in the Clinical Practice Research Datalink. The team found that people with dementia who were consistently seen by the same GP over the course of one year were given fewer medicines and were less likely to be given medicines that can cause problems like incontinence, drowsiness and falls. Those seeing the same GP over time were 35 per cent less likely to develop delirium, a state of confusion commonly experienced in dementia. Those who consistently saw the same GP were also 58 per cent less likely to experience incontinence, and almost ten per cent less likely to have an emergency hospitalisation, compared to those who had the most variation in GPs treating them.

The research was conducted in anonymised patient records of people with dementia aged 65 and over in 2016, who were followed-up for one year. This study includes people who visited a GP at least three times in the previous year.

Lead author Dr João Delgado, of the University of Exeter, said: "The number of people with dementia has been rising steadily and it is now one of the leading causes of death in the UK. In the absence of a cure, long-term care is particularly important. Treating people with dementia can be complex, because it often occurs together with other common diseases. Our research shows that seeing the same general practitioner consistently over time is associated with improved safe prescribing and improved health outcomes. This could have important healthcare impacts, including reduced treatment costs and care needs."

Delirium (an episode of more severe confusion) is common in dementia, and patients who develop delirium are more likely to die. Delirium and incontinence are very distressing for individuals, and require additional NHS resource. Extra hospital admissions are a high cost for the NHS.

Sir Denis Pereira Gray, co-author and GP researcher at the St Leonard's Practice, said: "These new findings show that GP continuity is associated with important benefits for patients. Whilst national policy makers have for years discouraged continuity, general practices can still provide good GP continuity through their internal practice organisation, for example, by using personal lists."

Dr Richard Oakley, Associate Director of Research at Alzheimer's Society said: "For the 900,000 people living with dementia in the UK, it's likely dementia isn't the only condition they're getting treatment for.

"It's clear from this study that consistently seeing the same GP has real benefits for people living with dementia -- better management and treatment of conditions, and lower risk of complications like delirium and incontinence, leading to improved quality of life.

"The pandemic has put GP services under immense pressure, so while we might not be able to get consistent GP care for everyone with dementia tomorrow, policymakers should absolutely be working with the NHS to build this into their plans as we emerge from the pandemic."

https://www.sciencedaily.com/releases/2022/01/220124194931.htm

Dementia: How to prevent cognitive decline

January 20, 2022

Science Daily/University of Montreal

Physical activity, nutrition and cognitively stimulating activities are all known to be good ways to prevent Alzheimer's disease and dementia. And older adults at risk can access a variety of lifestyle services to that end, including diet regimes and exercises for their body and mind.

Now an international team of researchers led by Université de Montréal psychology professor Sylvie Belleville has determined how many of those intervention sessions are needed prevent cognitive decline in people at risk: only about a dozen.

Published in Alzheimer's & Dementia : The Journal of the Alzheimer's Association, the study by Dr. Belleville and colleagues at the universities of Toulouse and Helsinki show that 12 to 14 sessions are all that's were needed to observe an improvement in cognition. Until now, the number of sessions or "doses" needed for optimal effect has been unknown.

"In pharmacological studies, every effort is made to define an optimal treatment dose needed to observe the expected effects, " said Belleville, a neuropsychologist and researcher at the research centere of the UdeM-affiliated Institut universitaire de gériatrie de Montréal. "This is rarely done in non-pharmacological studies, especially those on the prevention of cognitive decline, where little information is available to identify this dose.

"Defining an optimal number of treatment sessions is therefore crucial.," she continued. "Indeed, proposing too few sessions will produce no noticeable improvement effects, but too many sessions is also undesirable as these interventions are costly. They are costly both for the individual who follows the treatments, in terms of time and involvement, and for the organization offering these treatments."

The study is based on a secondary analysis of data from the three-year Multidomain Alzheimer Preventive Trial (MAPT) and looked at 749 participants who received a range of interventions aimed at preventing cognitive decline. These included dietary advice, physical activity and cognitive stimulation to improve or maintain physical and cognitive abilities.

People's individuality important

In their research, Belleville's team noted that people's individuality should be considered when determining the optimal treatment dose.

In their study, the researchers evaluated the effects of the sessions in terms of each participant's age, gender, education level, and cognitive and physical condition. The relationship between the "dose" each received and their cognitive improvement was then analyzed.

The main results show an increase with dose followed by a plateau effect after 12 to 14 sessions. In other words, you need enough dose to see an effect but offering more than 12 to 14 sessions of treatment does not mean better results. That said, participants with lower levels of education or more risk factors for frailty did benefit from more sessions.

The conclusion? It's important to identify and target an optimal dose and to customize the treatment for each individual, the researchers say. Not only is "dosage" an important component of behavioural interventions, it can also provide valuable information when time and money are limited, helping public-health agencies develop effective prevention programs and offer guidance to older adults and clinicians.

https://www.sciencedaily.com/releases/2022/01/220120091141.htm

Study may help clinicians use sleep brain wave patterns to diagnose dementia and other forms of cognitive impairment

Researchers define parameters for automated detection methods.

January 12, 2022

Science Daily/Massachusetts General Hospital

Certain brain wave patterns that occur while an individual sleeps may be assessed by clinicians to help them diagnose dementia and other conditions related to memory, language, and thinking. A new study published in Sleep that was led by investigators at Massachusetts General Hospital (MGH) and Beth Israel Deaconess Medical Center (BIDMC) could help improve automated methods for detecting these brain wave patterns, or sleep spindles, and for correlating them with cognitive function.

Sleep spindles are bursts of brain activity that occur during non-REM sleep and can be assessed through electroencephalograms (EECs) involving non-invasive electrodes placed on the scalp. Spindles are considered a "fingerprint" that vary among individuals, are highly heritable, and tend to be consistent from night to night.

"With the rising burden of neurodegenerative disease, there is a pressing need for a sensitive biomarker of cognition. This has led to a surge of research examining sleep spindles, an oscillatory pattern of brain activity observed during sleep, and their role in various neuropsychiatric conditions and cognitive performance," says lead author Noor Adra, a clinical research coordinator at MGH.

Although sleep spindles and other brain features represent promising potential electrophysiologic markers of neurodegenerative and psychiatric diseases, detecting and assessing sleep spindles is not straightforward. "People have already known that these transient high frequency events during sleep in the brain are closely linked to cognition, especially to learning and memory. But when you try to detect spindles among more than 100 sleep recordings, things become less clear -- such as what is the best threshold, what is the best minimum duration, etc.," says co-author Haoqi Sun, PhD, an investigator in the department of Neurology at MGH.

Sleep spindles are typically analyzed through visual inspection of EEGs, but automated methods can offer more consistent results. No consensus exists for parameters for such automated methods, however.

To address these issues, the investigators designed sleep-related experiments involving 167 adults to characterize how spindle detection parameter settings influence the association between spindle features and cognition and identified parameters that best correlate with cognitive performance.

The team also found that sleep spindles were most strongly linked with what's known as fluid intelligence, which relies on abstract thinking and problem-solving skills and declines during early stages of dementia. "Therefore, our findings support sleep spindles as a sleep-based biomarker of fluid cognition," says Adra. "By optimizing the detection of this proposed sleep-based biomarker of cognition, we hope to guide future studies that examine the sensitivity of this biomarker in neurodegenerative populations."

"Sleep spindles are one among many important measurable features of brain activity during sleep that provide a window into the brain's current state of health and individuals' risk for developing brain disease or cognitive decline. Now that we better understand how to measure sleep spindles, we can add these into a growing arsenal of brain health indicators that can be measured during sleep," adds co-senior author M. Brandon Westover, MD, PhD, an investigator in the department of Neurology at MGH and director of Data Science at the MGH McCance Center for Brain Health. "These indicators will be essential tools in our quest to develop treatments that can preserve and enhance brain heath."

https://www.sciencedaily.com/releases/2022/01/220112105627.htm