1. Study suggests exercise can help with boosting mood

    May 23, 2017 by Ashley

    From the University of Connecticut press release:

    You don’t have to spend hours at the gym or work up a dripping sweat to improve your mood and feel better about yourself, researchers at the University of Connecticut say in a new study.

    If you lead a sedentary lifestyle — spending large parts of your day sitting at home or at work — simply getting out of your chair and moving around can reduce depression and lift your spirits.

    “We hope this research helps people realize the important public health message that simply going from doing no physical activity to performing some physical activity can improve their subjective well-being,” says Gregory Panza, a graduate student in UConn’s Department of Kinesiology and the study’s lead author.

    “What is even more promising for the physically inactive person is that they do not need to exercise vigorously to see these improvements,” Panza continues. “Instead, our results indicate you will get the best ‘bang for your buck’ with light or moderate intensity physical activity.”

    For those keeping score, light physical activity is the equivalent of taking a leisurely walk around the mall with no noticeable increase in breathing, heart rate, or sweating, says Distinguished Kinesiology Professor Linda Pescatello, senior researcher on the project. Moderate intensity activity is equivalent to walking a 15-20-minute mile with an increase in breathing, heart rate, and sweating, yet still being able to carry on a conversation. Vigorous activity is equivalent to a very brisk walk or jogging a 13-minute mile with a very noticeable increase in breathing, heart rate, and sweating to the point of being unable to maintain a conversation.

    The study looked at 419 generally healthy middle-aged adults who wore accelerometers on their hips to track physical activity over four days. Participants also completed a series of questionnaires asking them to describe their daily exercise habits, psychological well-being, depression level, pain severity, and extent to which pain interfered with their daily activities.

    Here’s what the researchers learned:

    • People who reported higher levels of sedentary behavior also reported lower levels of subjective well-being, meaning those who sat around a lot were the least happiest. Subjective well-being is defined as the positive and negative evaluations that people make of their own lives. These results confirmed previous studies.
    • In general, physical activity improved people’s sense of well-being. Yet, different intensities of physical activity were more beneficial to some people than others. For instance, people who participated in light-intensity physical activity reported higher levels of psychological well-being and lower levels of depression. People who participated in moderate-intensity physical activity reported higher levels of psychological well-being and lower levels of pain severity.
    • People who led sedentary lives and engaged in light or moderate physical activity showed the greatest improvement in overall sense of well-being. “The ‘more is better’ mindset may not be true when it comes to physical activity intensity and subjective well-being,” says Panza. “In fact, an ‘anything is better’ attitude may be more appropriate if your goal is a higher level of subjective well-being.”
    • While light and moderate physical activity clearly made some people feel better about themselves, when it came to vigorous activity, the results were neutral. There was no positive or negative association found between high intensity physical activity and subjective well-being.

    The last finding is actually good news for folks who enjoy hard, calorie-burning workouts, as it doesn’t support a widely reported recent study that found high intensity workouts significantly lowered some people’s sense of well-being.

    “Recent studies had suggested a slightly unsettling link between vigorous activity and subjective well-being,” says Beth Taylor, associate professor of kinesiology and another member of the research team. “We did not find this in the current study, which is reassuring to individuals who enjoy vigorous activity and may be worried about negative effects.”

    Many previous studies have attempted to identify the best exercise regimen to improve people’s sense of well-being. Yet no clear consensus has emerged. Some studies say moderate or vigorous activity is best. Others say low intensity exercise is better. The differences, the UConn researchers say, may be due to the way the studies were designed and possible limitations in how people’s well-being and levels of physical activity were measured.

    The UConn study is believed to be the first of its kind to use both objective (accelerometers) and subjective (questionnaires) measurements within a single group to examine the relationship between physical activity intensity and well-being.

    Yet the UConn research also has its limits, Panza says.

    All of the individuals who participated in the UConn study had a generally positive sense of well-being going into the project and were generally physically active. So their answers in the questionnaires need to be framed in that context. Whether the same results would hold true for people with lower subjective well-being or lower levels of physical activity is unknown, Panza says.

    Also, the conclusions formed in the UConn study are based on information gathered at a single point in time. A longitudinal study that tracks people’s feelings and physical activity over time would go a long way toward helping determine what exercise regimen might be best for different populations, Panza said.

    “If it doesn’t make us feel good, we don’t want to do it,” says Taylor. “Establishing the link between different types, doses, and intensities of physical activity on well-being is a very important step in encouraging more people to exercise.”

    The study was published in the Journal of Health Psychology in February.


  2. Exercise study offers hope in fight against Alzheimer’s

    May 10, 2017 by Ashley

    From the University of Maryland press release:

    Could the initiation of a simple walking exercise program help older adults to reverse declines in key brain regions? A new study led by University of Maryland School of Public Health researchers adds more information about how physical activity impacts brain physiology and offers hope that it may be possible to reestablish some protective neuronal connections. Dr. J. Carson Smith, associate professor of kinesiology, and colleagues explored how a 12-week walking intervention with older adults, ages 60-88, affected functionality of a brain region known to show declines in people suffering from mild cognitive impairment (MCI) or Alzheimer’s disease.

    “The brain’s posterior cingulate cortex (PCC)/precuneus region is a hub of neuronal networks which integrates and disperses signals,” explains Dr. J. Carson Smith, senior author of the paper published in the Journal of Alzheimer’s Disease and director of the Exercise for Brain Health Laboratory. “We know that a loss of connectivity to this hub is associated with memory loss and amyloid accumulation, both signs of MCI and Alzheimer’s.”

    For this reason, reduced connectivity to the PCC/precuneus region is seen as a potential biomarker to detect cognitive impairment even before symptoms of MCI or AD may appear. It is also a potential target to test the effectiveness of interventions such as exercise to improve brain function in those exhibiting symptoms of MCI.

    Dr. Smith’s research team recruited two groups — one with 16 healthy elders and another with 16 elders diagnosed with mild cognitive impairment to participate in an exercise intervention that included walking for 30 minutes, four times a week (at 50-60 % of heart rate reserve) for three months.

    Before and after the exercise intervention, participants in both groups underwent fMRI brain scans to assess functional connectivity between multiple brain regions and the PCC/precuneus. After completing the intervention, both groups showed improved ability to remember a list of words; however only the MCI group showed increased connectivity to the PCC/precuneus hub, which was evident in 10 regions spanning the frontal, parietal, temporal and insular lobes, and the cerebellum.

    “These findings suggest that the protective effects of exercise training on cognition may be realized by the brain re-establishing communication and connections among the brain’s so-called default mode network, which may possibly increase the capacity to compensate for the neural pathology associated with Alzheimer’s disease,” said Dr. Smith.

    While it is unclear yet whether the effects of exercise training can delay further cognitive decline in patients diagnosed with MCI, the neural network connectivity changes documented in this study provide hope that exercise training may stimulate brain plasticity and restore communication between brain regions that may have been lost through Alzheimer’s disease. The specificity of these effects in the MCI group further suggest that exercise may be particularly useful in those who have already experienced mild memory loss. Future studies planned by Dr. Smith’s team aim to include exercise control conditions, and to incorporate exercise combined with cognitive engagement, among healthy older adults who are at increased risk for Alzheimer’s disease.


  3. Brain tissue structure could explain link between fitness and memory

    May 7, 2017 by Ashley

    From the University of Illinois at Urbana-Champaign press release:

    Studies have suggested a link between fitness and memory, but researchers have struggled to find the mechanism that links them. A new study by University of Illinois researchers found that the key may lie in the microstructure of the hippocampus, a region in the middle of the brain involved in memory processes.

    Aron Barbey, a professor of psychology, led a group of researchers at the Beckman Institute for Advanced Science and Technology at Illinois that used a specialized MRI technique to measure the structural integrity of the hippocampus in healthy young adults and correlated it with their performances on fitness and memory tests. They found that viscoelasticity, a measure of structural integrity in brain tissue, was correlated with fitness and memory performance — much more so than simply looking at the size of the hippocampus.

    “Using a new tool to examine the integrity of the hippocampus in healthy young adults could tell us more about how this region functions and how to predict decline for early intervention,” Barbey said. “By the time we look at diseased states, it’s often too late.”

    Prior research led by Illinois psychology professor Neal Cohen, who is also a co-author on the new paper, demonstrated that the hippocampus is critical for relational memory and that the integrity of this region predicts a host of neurodegenerative diseases. To date, much research on the hippocampus’ structure has focused on its size.

    Studies in developing children and declining older adults have found strong correlations between hippocampal size and memory. However, size does not seem to matter as much in healthy young adults, said postdoctoral researcher Hillary Schwarb. The Illinois group looked instead at the microstructure of the tissue, using an emerging neuroimaging tool called magnetic resonance elastography. The method involves an MRI scan, but with a pillow under the subject’s head vibrating at a very low amplitude — as gentle as driving on the interstate, Schwarb said. The vibration is the key to measuring the structural integrity of the hippocampus.

    “It’s a lot like sending ripples through a still pond — if there’s some large thing like a boulder under the surface, the ripples are going to displace around it,” Schwarb said. “We are sending waves through the brain and reconstructing the displacements into a map we can look at and measure.”

    The study, published in the journal NeuroImage, found that those who performed better on the fitness test tended to also perform better on the memory task, confirming a correlation the group had noticed before. But by adding the information on the structure of the hippocampus, the researchers were able to find a possible pathway for the link. They found that the subjects with higher fitness levels also had more elastic tissue in the hippocampus. The tissue structure, in turn, was associated with memory.

    “We found that when the hippocampus is more elastic, memory is better. An elastic hippocampus is like a firm foam mattress pad that pops right back up after you get up,” said study co-author Curtis Johnson, a former graduate researcher at the Beckman Institute who is now a professor at the University of Delaware. “When the hippocampus is more viscous, memory is worse. A viscous hippocampus is like a memory-foam mattress that holds its shape even after you get up.”

    The results suggest that the viscoelasticity of the hippocampus may be the mediating factor in the relationship between fitness and memory in healthy young adults.

    “It also shows us that magnetic resonance elastography is a useful tool for understanding tissue microstructure, and that microstructure is important to cognition,” Schwarb said. “This provides us a new level of analysis for studying the human brain.”


  4. Aerobic, resistance exercise combo can boost brain power of over 50s

    May 2, 2017 by Ashley

    From the BMJ press release:

    A combination of aerobic and resistance exercises can significantly boost the brain power of the over 50s, finds the most comprehensive review of the available evidence to date, published online in the British Journal of Sports Medicine.

    And the effects were evident irrespective of the current state of an individual’s brain health, the analysis shows.

    Physical exercise for older adults is seen as a promising means of warding off or halting a decline in brain health and cognitive abilities. Yet the evidence for its benefits is inconclusive, largely because of overly restrictive inclusion criteria in the reviews published to date, say the researchers.

    In a bid to try and plug some of thes
    e gaps, they systematically reviewed 39 relevant studies published up to the end of 2016 to assess the potential impact of varying types, intensities, and durations of exercise on the brain health of the over 50s.

    They included aerobic exercise; resistance training (such as weights); multi-component exercise, which contains elements of both aerobic and resistance training; tai chi; and yoga in their analysis.

    They analysed the potential impact of these activities on overall brain capacity (global cognition); attention (sustained alertness, including the ability to process information rapidly); executive function (processes responsible for goal oriented behaviours); memory (storage and retrieval); and working memory (short term application of found information).

    Pooled analysis of the data showed that exercise improves the brain power of the over 50s, irrespective of the current state of their brain health.

    Aerobic exercise significantly enhanced cognitive abilities while resistance training had a pronounced effect on executive function, memory, and working memory.

    The evidence is strong enough to recommend prescribing both types of exercise to improve brain health in the over 50s, say the researchers.

    The data showed that tai chi also improved cognitive abilities, which backs the findings of previously published studies, but the analysis was based on just a few studies, caution the researchers, so will need to be confirmed in a large clinical trial.

    Nevertheless, it’s an important finding, they suggest, because exercises like tai chi may be suitable for people who are unable to do more challenging forms of physical activity.

    And in terms of how much and how often, the data analysis showed that a session lasting between 45 and 60 minutes, of moderate to vigorous intensity, and of any frequency, was good for brain health.

    The researchers point to some potential limitations of their review: their evidence was confined only to studies of supervised exercise and which had been published in English.

    Nevertheless, they conclude: “The findings suggest that an exercise programme with components of both aerobic and resistance type training, of at least moderate intensity and at least 45 minutes per session, on as many days of the week as possible, is beneficial to cognitive function in adults aged over 50.”


  5. How walking benefits the brain

    April 30, 2017 by Ashley

    From the Experimental Biology 2017 press release:

    You probably know that walking does your body good, but it’s not just your heart and muscles that benefit. Researchers at New Mexico Highlands University (NMHU) found that the foot’s impact during walking sends pressure waves through the arteries that significantly modify and can increase the supply of blood to the brain. The research will be presented today at the APS annual meeting at Experimental Biology 2017 in Chicago.

    Until recently, the blood supply to the brain (cerebral blood flow or CBF) was thought to be involuntarily regulated by the body and relatively unaffected by changes in the blood pressure caused by exercise or exertion. The NMHU research team and others previously found that the foot’s impact during running (4-5 G-forces) caused significant impact-related retrograde (backward-flowing) waves through the arteries that sync with the heart rate and stride rate to dynamically regulate blood circulation to the brain.

    In the current study, the research team used non-invasive ultrasound to measure internal carotid artery blood velocity waves and arterial diameters to calculate hemispheric CBF to both sides of the brain of 12 healthy young adults during standing upright rest and steady walking (1 meter/second). The researchers found that though there is lighter foot impact associated with walking compared with running, walking still produces larger pressure waves in the body that significantly increase blood flow to the brain. While the effects of walking on CBF were less dramatic than those caused by running, they were greater than the effects seen during cycling, which involves no foot impact at all.

    “New data now strongly suggest that brain blood flow is very dynamic and depends directly on cyclic aortic pressures that interact with retrograde pressure pulses from foot impacts,” the researchers wrote. “There is a continuum of hemodynamic effects on human brain blood flow within pedaling, walking and running. Speculatively, these activities may optimize brain perfusion, function, and overall sense of wellbeing during exercise.”

    “What is surprising is that it took so long for us to finally measure these obvious hydraulic effects on cerebral blood flow,” first author Ernest Greene explained. “There is an optimizing rhythm between brain blood flow and ambulating. Stride rates and their foot impacts are within the range of our normal heart rates (about 120/minute) when we are briskly moving along.”


  6. Study suggests beetroot juice may help increase brain efficiency in older adults

    April 27, 2017 by Ashley

    From the Wake Forest University press release:

    Drinking a beetroot juice supplement before working out makes the brain of older adults perform more efficiently, mirroring the operations of a younger brain, according to a new study by scientists at Wake Forest University.

    “We knew, going in, that a number of studies had shown that exercise has positive effects on the brain,” said W. Jack Rejeski, study co-author. “But what we showed in this brief training study of hypertensive older adults was that, as compared to exercise alone, adding a beet root juice supplement to exercise resulted in brain connectivity that closely resembles what you see in younger adults.”

    While continued work in this area is needed to replicate and extend these exciting findings, they do suggest that what we eat as we age could be critically important to the maintenance of our brain health and functional independence.

    Rejeski is Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science. The study, “Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain,” was published in the peer-reviewed Journals of Gerontology: Medical Sciences. One of his former undergraduate students, Meredith Petrie, was the lead author on the paper.

    This is the first experiment to test the combined effects of exercise and beetroot juice on functional brain networks in the motor cortex and secondary connections between the motor cortex and the insula, which support mobility, Rejeski said.

    The study included 26 men and women age 55 and older who did not exercise, had high blood pressure, and took no more than two medications for high blood pressure. Three times a week for six weeks, they drank a beetroot juice supplement called Beet-It Sport Shot one hour before a moderately intense, 50-minute walk on a treadmill. Half the participants received Beet-It containing 560 mg of nitrate; the others received a placebo Beet-It with very little nitrate.

    Beets contain a high level of dietary nitrate, which is converted to nitrite and then nitric oxide (NO) when consumed. NO increases blood flow in the body, and multiple studies have shown it can improve exercise performance in people of various ages.

    “Nitric oxide is a really powerful molecule. It goes to the areas of the body which are hypoxic, or needing oxygen, and the brain is a heavy feeder of oxygen in your body,” said Rejeski.

    When you exercise, the brain’s somatomotor cortex, which processes information from the muscles, sorts out the cues coming in from the body. Exercise should strengthen the somatomotor cortex.

    So, combining beetroot juice with exercise delivers even more oxygen to the brain and creates an excellent environment for strengthening the somatomotor cortex. Post-exercise analysis showed that, although the study groups has similar levels of nitrate and nitrite in the blood before drinking the juice, the beetroot juice group had much higher levels of nitrate and nitrite than the placebo group after exercise.


  7. Study suggests walking up and down stairs may be more energizing than caffeine

    by Ashley

    From the University of Georgia press release:

    A midday jolt of caffeine isn’t as powerful as walking up and down some stairs, according to new research from the University of Georgia.

    In a new study published in the journal Physiology and Behavior, researchers in the UGA College of Education found that 10 minutes of walking up and down stairs at a regular pace was more likely to make participants feel energized than ingesting 50 milligrams of caffeine-about the equivalent to the amount in a can of soda.

    “We found, in both the caffeine and the placebo conditions, that there was not much change in how they felt,” said Patrick J. O’Connor, a professor in the department of kinesiology who co-authored the study with former graduate student Derek Randolph. “But with exercise they did feel more energetic and vigorous. It was a temporary feeling, felt immediately after the exercise, but with the 50 milligrams of caffeine, we didn’t get as big an effect.”

    The study aimed to simulate the hurdles faced in a typical office setting, where workers spend hours sitting and staring at computer screens and don’t have time for a longer bout of exercise during the day. For the study, participants on separate days either ingested capsules containing caffeine or a placebo, or spent 10 minutes walking up and down stairs-about 30 floors total-at a low-intensity pace.

    O’Connor wanted to compare an exercise that could be achieved by people in an office setting, where they have access to stairs and a little time to be active, but not enough time to change into workout gear, shower and change back into work clothes.

    “Office workers can go outside and walk, but weather can be less than ideal. It has never rained on me while walking the stairs,” said O’Connor. “And a lot of people working in office buildings have access to stairs, so it’s an option to keep some fitness while taking a short break from work.”

    Study participants were female college students who described themselves as chronically sleep deprived-getting less than 6½ hours per night. To test the effects of caffeine versus the exercise, each group took some verbal and computer-based tests to gauge how they felt and how well they performed certain cognitive tasks. Neither caffeine nor exercise caused large improvements in attention or memory, but stair walking was associated with a small increase in motivation for work.

    O’Connor added that there is still much research to be done on the specific benefits of exercising on the stairs, especially for just 10 minutes. But even a brief bout of stair walking can enhance feelings of energy without reducing cognitive function. “You may not have time to go for a swim, but you might have 10 minutes to walk up and down the stairs.”


  8. Adolescents with frequent PE more informed about physical activity’s role in health

    April 15, 2017 by Ashley

    From the Oregon State University press release:

    Frequent, long-term instruction in physical education not only helps adolescents be more fit but also equips them with knowledge about how regular physical activity relates to good health, research at Oregon State University shows.

    The findings are important for several reasons. One is that regular physical education, which is on the decline nationwide, strongly correlated with students meeting the federal recommendation of at least 60 minutes per day of moderate to vigorous physical activity.

    The results also showed more than one adolescent in five reported no physical education at all; nearly 40 percent of the students in the 459-person sample, whose ages ranged from 12 to 15, were obese or overweight; and only 26.8 percent met the federal government’s physical activity guidelines.

    “Perhaps some were not meeting the guidelines because fewer than 35 percent actually knew what the guidelines were for their age group,” said study co-author Brad Cardinal, a professor in OSU’s School of Biological and Population Health Sciences and a nationally recognized expert on the benefits of exercise.

    The guidelines call for an hour or more of physical activity at least five days a week.

    The findings by OSU’s College of Public Health and Human Sciences indicate that a trend of decline in physical education mandates for middle-school students is detrimental to developing the knowledge, interests and skills that serve as a foundation for a lifelong healthy lifestyle.

    Physical activity also has been shown to improve cognitive function and academic performance, Cardinal said.

    “We have the physical activity guidelines for a reason, and they’re based on good science,” he said. “With only slightly more than one in four adolescents meeting the guidelines, today’s youth are being shortchanged in terms of their holistic development. They are not being prepared to live the proverbial good life.”

    Cardinal notes that new guidelines will be released in 2018.

    “Because of a growing propensity toward inactivity in daily life, such as increased media consumption and screen time, the guidelines very well may have to be ratcheted up to compensate,” Cardinal said.

    Like physical education, participation in sports also correlated with more accurate student perceptions of the amount of physical activity necessary for good health, as well as better performance on a variety of muscular fitness-related tests.

    “This underscores the importance of quality physical education in schools and the added value of sports participation,” Cardinal said. “The junior high/middle school years are a vulnerable and pivotal time in which students are typically required to take at least some physical education for at least part of the year, whereas after their freshman year in high school, most students aren’t required to take any. It’s a time when experiences in physical education and sports, whether positive or negative, can make or break whether an adolescent chooses to continue a physically active lifestyle.”

    Cardinal points out that in Oregon, 2017 is supposed to represent the final year in a decade-long, statute-mandated ramp-up of physical education in public schools, but the reality is something different.

    Portland Public Schools, he noted, just announced a cutback to 30 minutes of physical education every other week, whereas the law calls for 225 minutes per week for middle school students and 150 for elementary school students.

    “In the federal Every Student Succeeds Act, physical education is a core subject, on par with language, math and science. Its status was elevated for a reason,” Cardinal said. “If you’re physically active, you’re going to be healthier and stronger and have fewer behavioral problems, and your cognitive function is going to be better.

    “Physical education trumps sports in a head-to-head comparison of the two,” he added, “and when you have physical education plus sports, that’s when you have students who are the healthiest, fittest, strongest and most active.”

    Findings were published in the American Journal of Health Promotion.


  9. How physical exercise aids in stroke recovery

    December 15, 2016 by Ashley

    From the Frontiers media release:

    The after-effects of a stroke can be life changing. Paralysis, speech problems and memory loss occur in varying degrees of severity, depending on the location and amount of brain tissue damage.

    How far a stroke patient can recover is largely determined by the ability of the brain to reorganise itself. Understanding what can improve this ability is therefore essential in developing the best therapies for rehabilitation.

    Voluntary physical exercise is known to have a positive effect on a person’s overall well-being. It delays memory loss in old age and improves cognitive ability. A new study, published in the open-access journal Frontiers in Aging Neuroscience, has linked the positive effects of exercise on the brains of mice to their better recovery after a stroke.

    Our study suggests that physical exercise can be used as a preventive, as well as a therapeutic approach to aid recovery after a cortical stroke,” says Dr. Evgenia Kalogeraki, who conducted this research at the in the laboratory of Prof. Dr. Siegrid Löwel, at Georg-August-University, Germany.

    Previous research of the Löwel laboratory has shown that mice growing up in an enriched environment, such as free access to a running wheel and increased cognitive and social stimulation, retain a more youthful brain into adulthood. In their new study, the researchers wanted to see if physical exercise alone could have these benefits, and in addition, protect and potentially rehabilitate the brain after a stroke had occurred.

    In order to do this, Kalogeraki and her co-authors used a standard test to assess the brain’s ‘plasticity’ — its ability to change the way it activates in response to an experience. When the visual input of one eye is compromised for a couple of days, then the part of the brain that processes visual information gets preferentially activated by the other, open eye. The brain’s ability to change eye dominance (called ocular dominance plasticity) is age-related, being most pronounced in juvenile animals and completely absent in older mice that have been raised without any stimulation.

    As well as confirming existing knowledge about the anti-aging effects of voluntary physical exercise — older mice that exercised retained the ability to change eye dominance in comparison to those that didn’t — the study also revealed some exciting new findings. Those mice that had free-access to a running wheel were able to maintain ocular dominance plasticity after suffering a stroke, compared to those that didn’t.

    We found that mice with free access to a running wheel throughout their life preserved a more juvenile brain into adulthood and were able to prevent the negative effects of a stroke,” reveals Kalogeraki.

    That was not all — in addition, the researchers observed that exercise could even be used therapeutically after suffering a stroke. “We also found that mice with no previous access to a running wheel showed an equally positive recovery if voluntary exercise started after a stroke had occurred,” adds Dr. Justyna Pielecka-Fortuna, co-author of the study.

    These exciting observations have the potential to provide a simple but effective method to protect and rehabilitate patients that are prone to, or have already suffered, a stroke.

    The senior author of this study, has been so inspired by this research she has taken up exercising again. “The fact that the brain can restore its youthfulness by starting physical exercise after a stroke has occurred suggests that it is never too late to benefit from exercise,” says Löwel. “I’ve started cycling again — what is good for the mice cannot be bad for me!”

    It is hoped this research will expand our knowledge of how physical exercise can have such a positive influence on the brain. “We now hope to study the mechanisms underlying exercise-mediated activity changes in the brain, to ultimately better guide studies in humans” concludes Kalogeraki.

     


  10. Moderate exercise improves memory dysfunction caused by type 2 diabetes

    December 14, 2016 by Ashley

    From the University of Tsukuba media release:

    diabetes blood sugarUniversity of Tsukuba-led researchers show that moderate exercise may improve hippocampal memory dysfunction caused by type 2 diabetes and that enhanced transport of lactate to neurons may be the underlying mechanism

    Type 2 diabetes is characterized by impaired glucose metabolism and can cause central nervous system-related complications, such as memory dysfunction. The hippocampus is an essential brain component for normal memory formation. However, the effect of impaired glycometabolism on hippocampal-mediated memory in type 2 diabetes patients is not known.

    In a new study, researchers centered at the University of Tsukaba investigated whether hippocampal glucose metabolism and memory function is altered in a rat model of type 2 diabetes. Based on the idea that exercise normalizes glycometabolism and improves memory function, the research team also investigated the effects of exercise on hippocampal glycometabolism and memory formation.

    Hippocampal function was evaluated by placing the rat in a circular pool and testing its ability to remember the location of a platform that would allow it to escape from the water. “This is a well-established method for measuring spatial learning and memory,” study first author Takeru Shima says.

    Type 2 diabetic rats needed more time to escape the water and find the platform. However, after 4 weeks of moderate exercise, they were able to find the platform much faster. “This indicated that exercise significantly improved spatial memory impairments in type 2 diabetic rats,” Shima explains.

    Glycogen levels are altered in tissues of diabetes patients, leading to a variety of complications. However, glycogen levels have not yet been investigated in the hippocampus. “We showed for the first time that glycogen levels are significantly higher in the hippocampus of diabetic rats,” corresponding author Hideaki Soya says.

    Interestingly, single bout of exercise reduced hippocampal glycogen levels and this correlated with an increase in lactate levels. Lactate is an energy substrate and neuromodulator in the hippocampus, and is known to enhance memory formation. Lactate is transferred to neurons through monocarboxylate transporters (MCTs). “MCT2 expression was significantly lower in the hippocampus of type 2 diabetic rats,” Soya says, “dysregulated MCT2-mediated neuronal uptake of lactate is a possible aetiology of memory dysfunction in type 2 diabetes, and that elevated hippocampal glycogen may be an adaptive change to compensate for the decreased lactate utilization.”

    4 weeks of moderate exercise further enhanced glycogen levels and normalized MCT2 expression in the hippocampus of type 2 diabetic rats.” These findings suggest that disrupted MCT2-mediated uptake of lactate by neurons contributes to memory dysfunction in type 2 diabetic rats.

    The findings indicate that moderate exercise could be used to treat memory impairment in patients with type 2 diabetes by promoting the transfer of glycogen-derived lactate to hippocampal neurons.