rhythm-science

When you listen to music, multiple areas of your brain are lighting up at once as they process sound, take it apart to understand elements like melody and rhythm, and then put it all back together into unified musical experience. And our brains do all this work in the split second between when we first hear the music and when our foot starts to tap along. 

From the TED-Ed lesson How playing an instrument benefits your brain - Anita Collins

Animation by Sharon Colman Graham

Scientists Discover How We Play Memories in Fast Forward

Scientists at The University of Texas at Austin have discovered a mechanism that may explain how the brain can recall nearly all of what happened on a recent afternoon — or make a thorough plan for how to spend an upcoming afternoon — in a fraction of the time it takes to live out the experience. The breakthrough in understanding a previously unknown function in the brain has implications for research into schizophrenia, autism spectrum disorders, Alzheimer’s disease and other disorders where real experiences and ones that exist only in the mind can become distorted.

The newly discovered mechanism, which compresses information needed for memory retrieval, imagination or planning and encodes it on a brain wave frequency that’s separate from the one used for recording real-time experiences, is described in a cover article in the Jan. 20 print edition of the journal Neuron.

Brain cells share different kinds of information with one another using a variety of different brain waves, analogous to the way radio stations broadcast on different frequencies. Laura Colgin, an assistant professor of neuroscience, Chenguang Zheng, a postdoctoral researcher, and their colleagues found that one of these frequencies allows us to play back memories — or envision future activities — in fast forward.

“The reason we’re excited about it is that we think this mechanism can help explain how you can imagine a sequence of events you’re about to do in a time-compressed manner,” says Colgin. “You can plan out those events and think about the sequences of actions you’ll do. And all of that happens on a faster time scale when you’re imagining it than when you actually go and do those things.”

In the brain, fast gamma rhythms encode memories about things that are happening right now; these waves come rapidly one after another as the brain processes high-resolution information in real time. The scientists learned that slow gamma rhythms — used to retrieve memories of the past, as well as imagine and plan for the future — store more information on their longer waves, contributing to the fast-forward effect as the mind processes many data points with each wave.

Mental compression turns out to be similar to what happens in a computer when you compress a file. Just like digital compression, when you replay a mental memory or imagine an upcoming sequence of events, these thoughts will have less of the rich detail found in the source material. The finding has implications for medicine as well as for criminal justice and other areas where memory reliability can be at issue.

Colgin notes that the research could also explain why people with schizophrenia who are experiencing disrupted gamma rhythms have a hard time distinguishing between imagined and real experiences.

“Maybe they are transmitting their own imagined thoughts on the wrong frequency, the one usually reserved for things that are really happening,” says Colgin. “That could have terrible consequences.”

Next, the researchers plan to use animals with neurological disorders similar to autism spectrum disorders and Alzheimer’s disease in humans to better understand what role this mechanism plays and explore ways to counteract it.

Deconstructing mental illness through ultradian rhythms         

Might living a structured life with regularly established meal times and early bedtimes lead to a better life and perhaps even prevent the onset of mental illness? That’s what’s suggested in a study led by Kai-Florian Storch, PhD, of the Douglas Mental Health University Institute and McGill University, which has been published in the online journal eLife.

Our daily sleep-wake cycle is governed by an internal 24-hour timer, the circadian clock. However, there is evidence that daily activity is also influenced by rhythms much shorter than 24 hours, which are known as ultradian rhythms and follow a four-hour cycle.

These four-hour ultradian rhythms are activated by dopamine. When dopamine levels are out of kilter - as is suggested to be the case with people suffering from bipolar disease and schizophrenia - the four-hour rhythms can stretch as long as 48 hours.

With this study, conducted on genetically modified mice, Dr. Storch and his team demonstrate that sleep abnormalities, which in the past have been associated with circadian rhythm disruption, result instead from an imbalance of an ultradian rhythm generator (oscillator) that is based on dopamine. The team’s findings also offer a very specific explanation for the two-day cycling between mania and depression observed in certain bipolar cases: it is a result of the dopamine oscillator running on a 48-hour cycle.

This work is groundbreaking not only because of its discovery of a novel dopamine-based rhythm generator, but also because of its links to psychopathology. This new data suggests that when the ultradian arousal oscillator goes awry, sleep becomes disturbed and mania will be induced in bipolar patients; oscillator imbalance may likely also be associated with  schizophrenic episodes in schizophrenic subjects. The findings have potentially strong implications for the treatment of bipolar disease and other mental illnesses linked to dopamine dysregulation.

The work, entitled “A highly tunable dopaminergic oscillator generates ultradian rhythms of behavioral arousal,” has been funded by the Canadian Institutes of Health Research, the Natural Sciences Engineering and Research Council, and the Canadian Foundation for Innovation. To read the full paper: http://elifesciences.org/content/3/e05105

How Much Sleep Do You Really Need, and What Happens When You Don’t Get Enough?

Every March, we are all faced with the arrival of Daylight Saving Time and its impact on our circadian rhythms, our sleep-wake pattern. The 1-hour shift in time can even temporarily disrupt our ability to fall asleep at night and to wake up in the morning. We not only lose an hour of sleep, but the time change disrupts the body’s biological clock and circadian rhythm. The effect is the same as jetlag in plane travel, in which our bodies remain on the prior schedule for a period of time.  

“People who sleep well can usually adjust to the time shift with little difficulty,” says Jeffrey P. Barasch, M.D., Medical Director of The Valley Hospital Center for Sleep Medicine in Ridgewood, NJ. However, if someone has been coping with chronic difficulty sleeping, daylight saving time can worsen or uncover an undiagnosed and untreated sleep disorder, such as insomnia or sleep apnea.

It is important to keep in mind that the required amount of sleep per day changes with age, and studies indicate the following recommended sleep durations:

• Newborns — 16 to 18 hours a day
• Preschool-aged children — 11 to 12 hours a day
• School-aged children — at least 10 hours a day
• Teens — 9 to 10 hours a day
• Adults (age 20-64) — 7 to 9 hours a day
• Elderly (age 65 and over) — 7 to 8 hours a day

“Unfortunately, as you well know, sometimes life can prevent us from going to bed when we want to and many of us have experienced the frustration of not being able to fall asleep or stay asleep once we are in bed,” Dr. Barasch says. “Luckily, our bodies can adjust to occasional instances when we do not get enough sleep.”

But what happens when we are consistently not getting enough sleep? According to Dr. Barasch, sleep deprivation can impact the brain and every organ in the body.  During sleep, a newly discovered network of water channels in the brain, called the glymphatic system, becomes active and functions as a waste disposal system, carrying toxins away which would otherwise accumulate and damage brain cells. The accumulation of one of those toxins, amyloid-beta, is associated with Alzheimer’s disease.  

Dr. Barasch warns that those who suffer from chronic sleep deprivation, regardless of the reason, can experience adverse effects in many aspects of their lives. The lack of crucial restorative sleep can lead to daytime sleepiness, irritability, difficulty focusing, deterioration in work or school productivity, and impaired creativity and decision making. Sleep deprivation also affects performance and reaction time. Losing two hours of sleep is similar to the effect of alcohol intoxication. Sleep deprivation is also involved in many automobile, truck and airplane crashes. Lack of sleep also promotes weight gain and may lead to long term health consequences, such as depression, diabetes, hypertension, gastrointestinal disorders and colon cancer.  

So what do you do if your struggle with sleep isn’t limited to a change in the clocks?
If you are having difficulty sleeping, the National Institute of Health suggests incorporating some of the following strategies into your nighttime routine:

• Go to bed and wake up at the same time every day.
• Try to keep the same sleep schedule on weeknights and weekends.
• Use the hour before bed for quiet time.
• Avoid heavy and/or large meals within a couple hours of bedtime.
• Avoid alcoholic drinks, nicotine and caffeine before bed.
• Spend time outside every day (when possible) and be physically active.
• Keep your bedroom quiet, cool, and dark (a dim night light is fine, if needed).
• Take a hot bath or use relaxation techniques before bed.

If you regularly experience daytime drowsiness, fatigue or disturbed sleep, consider consulting with a sleep medicine specialist to evaluate and treat the problem.

Scientists discover what controls waking up and going to sleep

Fifteen years ago, an odd mutant fruit fly caught the attention and curiosity of Dr. Ravi Allada, a circadian rhythms expert at Northwestern University, leading the neuroscientist to recently discover how an animal’s biological clock wakes it up in the morning and puts it to sleep at night.

The clock’s mechanism, it turns out, is much like a light switch. In a study of brain circadian neurons that govern the daily sleep-wake cycle’s timing, Allada and his research team found that high sodium channel activity in these neurons during the day turn the cells on and ultimately awaken an animal, and high potassium channel activity at night turn them off, allowing the animal to sleep. Investigating further, the researchers were surprised to discover the same sleep-wake switch in both flies and mice.

“This suggests the underlying mechanism controlling our sleep-wake cycle is ancient,” said Allada, professor and chair of neurobiology in the Weinberg College of Arts and Sciences. He is the senior author of the study. “This oscillation mechanism appears to be conserved across several hundred million years of evolution. And if it’s in the mouse, it is likely in humans, too.”

Better understanding of this mechanism could lead to new drug targets to address sleep-wake trouble related to jet lag, shift work and other clock-induced problems. Eventually, it might be possible to reset a person’s internal clock to suit his or her situation.

The researchers call this a “bicycle” mechanism: two pedals that go up and down across a 24-hour day, conveying important time information to the neurons. That the researchers found the two pedals – a sodium current and potassium currents – active in both the simple fruit fly and the more complex mouse was unexpected.

The findings were published in the Aug. 13 issue of the journal Cell.

Matthieu Flourakis, Elzbieta Kula-Eversole, Alan L. Hutchison, Tae Hee Han, Kimberly Aranda, Devon L. Moose, Kevin P. White, Aaron R. Dinner, Bridget C. Lear, Dejian Ren, Casey O. Diekman, Indira M. Raman, Ravi Allada. A Conserved Bicycle Model for Circadian Clock Control of Membrane Excitability. Cell, 2015; 162 (4): 836 DOI: 10.1016/j.cell.2015.07.036

Sleeping mouse (stock image). “What is amazing is finding the same mechanism for sleep-wake cycle control in an insect and a mammal,” said Matthieu Flourakis, the lead author of the study. “Mice are nocturnal, and flies are diurnal, or active during the day, but their sleep-wake cycles are controlled in the same way.”        Credit: © Iosif Szasz-Fabian / Fotolia

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Does School Start Too Early?

by Mark Fischetti / Scientific American

Parents, students and teachers often argue, with little evidence, about whether U.S. high schools begin too early in the morning. In the past three years, however, scientific studies have piled up, and they all lead to the same conclusion: a later start time improves learning. And the later the start, the better.

Biological research shows that circadian rhythms shift during the teen years, pushing boys and girls to stay up later at night and sleep later into the morning. The phase shift, driven by a change in melatonin in the brain, begins around age 13, gets stronger by ages 15 and 16, and peaks at ages 17, 18 or 19.

SEE VIDEO OF RESTLESS SLEEP

Does that affect learning? It does, according to Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement at the University of Minnesota. She published a large study in February that tracked more than 9,000 students in eight public high schools in Minnesota, Colorado and Wyoming. After one semester, when school began at 8:35 a.m. or later, grades earned in math, English, science and social studies typically rose a quarter step—for example, up halfway from B to B+.

Two journal articles that Wahlstrom has reviewed but have not yet been published reach similar conclusions. So did a controlled experiment completed by the U.S. Air Force Academy, which required different sets of cadets to begin at different times during their freshman year. A 2012 study of North Carolina school districts that varied school times because of transportation problems showed that later start times correlated with higher scores in math and reading. Still other studies indicate that delaying start times raises attendance, lowers depression rates and reduces car crashes among teens, all because they are getting more of the extra sleep they need.

SEE SLEEP STUDY PHOTOS

And the later the delay, the greater the payoff. In various studies, school districts that shifted from 7:30 to 8:00 a.m. saw more benefits than those that shifted from 7:15 to 7:45 a.m. Studies in Brazil, Italy and Israel showed similar improvements in grades. The key is allowing teens to get at least eight hours of sleep, preferably nine. In Europe, it is rare for high school to start before 9:00 a.m.

Read the entire article

Images above © Science Source

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The cold never bothered me anyway (wait, that’s a lie). Keep warm with The Scope, your research rundown for the week of November 17:

  1. This will be the last time you forget your diet. Researchers at NYU Langone Medical Center recently found that female mice on low-calorie, low-carb diets were less prone to developing age-related diseases like Alzheimer’s and dementia.
  2. Circadian rhythm is our internal alarm clock that makes sure we’re awake during the day and asleep at night. If you’ve experienced jet lag, you know the pain of an out-of-sync circadian clock. Now, scientists show that permanently snoozing a malfunctioning circadian clock fixes memory problems in hamsters, a potential new treatment for patients with memory disorders. Twelve-hour time difference on your next vacation? Bring it on.
  3. Scientists have recently built the largest ever molecular “cage” using self-assembling proteins…basically like a bunch of Legos putting themselves together. With future work, these structures should be able to ferry large cargo into cells, such as novel vaccines and drugs.

Image: A specific area of the brain called the suprachiasmatic nucleus contains neurons (in green) that synchronize our circadian clock. Credit: Cristina Mazuski, Washington University in St. Louis.

The circadian clock is like an orchestra with many conductors

You’ve switched to the night shift and your weight skyrockets, or you wake at 7 a.m. on weekdays but sleep until noon on weekends—a social jet lag that can fog your Saturday and Sunday.

Life runs on rhythms driven by circadian clocks, and disruption of these cycles is associated with serious physical and emotional problems, says Orie Shafer, a University of Michigan assistant professor of molecular, cellular and developmental biology.

Now, new findings from Shafer and U-M doctoral student Zepeng Yao challenge the prevailing wisdom about how our body clocks are organized, and suggest that interactions among neurons that govern circadian rhythms are more complex than originally thought.

Yao and Shafer looked at the circadian clock neuron network in fruit flies, which is functionally similar to that of mammals, but at only 150 clock neurons is much simpler. Previously, scientists thought that a master group of eight clock neurons acted as pacemaker for the remaining 142 clock neurons—think of a conductor leading an orchestra—thus imposing the rhythm for the fruit fly circadian clock. It is thought that the same principle applies to mammals.

Interactions among clock neurons determine the strength and speed of circadian rhythms, Yao says. So, when researchers genetically changed the clock speeds of only the group of eight master pacemakers they could examine how well the conductor alone governed the orchestra. They found that without the environmental cues, the orchestra didn’t follow the conductor as closely as previously thought.

Some of the fruit flies completely lost sense of time, and others simultaneously demonstrated two different sleep cycles, one following the group of eight neurons and the other following some other set of neurons.

“The finding shows that instead of the entire orchestra following a single conductor, part of the orchestra is following a different conductor or not listening at all,” Shafer said.

The findings suggest that instead of a group of master pacemaker neurons, the clock network consists of many independent clocks, each of which drives rhythms in activity. Shafer and Yao suspect that a similar organization will be found in mammals, as well.

“A better understanding of the circadian clock mechanisms will be critical for attempts to alleviate the adverse effects associated with circadian disorders,” Yao said.

Disrupting the circadian clock through shift work is associated with diabetes, obesity, stress, heart disease, mood disorders and cancer, among other disorders, Yao says. The International Agency for Research on Cancer classified shift work that disrupts circadian rhythms as a human carcinogen equal to cancer-causing ultraviolet radiation.

Lipoic acid helps restore, synchronize the ‘biological clock’

Researchers have discovered a possible explanation for the surprisingly large range of biological effects that are linked to a micronutrient called lipoic acid: It appears to reset and synchronize circadian rhythms, or the “biological clock” found in most life forms.

The ability of lipoic acid to help restore a more normal circadian rhythm to aging animals could explain its apparent value in so many important biological functions, ranging from stress resistance to cardiac function, hormonal balance, muscle performance, glucose metabolism and the aging process.

The findings were made by biochemists from the Linus Pauling Institute at Oregon State University, and published in Biochemical and Biophysical Research Communications, a professional journal. The research was supported by the National Institutes of Health, through the National Center for Complementary and Alternative Medicine.

Caption: With age, circadian rhythms can lose their proper synchronization, and also become less pronounced. Credit: (Graphic courtesy of Oregon State University)

The Correspondent
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THE CORRESPONDENT // This song is about Lise Meitner, a brilliant scientist who discovered nuclear fission and also happened to be a woman (a fact which shut her out of the notoriety and reverence she deserved). As always, this song packs a pretty significant punch in the sensitive spot where my sentimentality sits. Alliteration and emotions aside, I’m proud of this noise, and all the hard work we all put into it. And then, don’t even get me started on elementals’ perfect Joni Mitchell-esque vocals on this. I couldn’t NOT have her sing on this one. Some things just make sense. This is just one of those things.

music by me, lyrics by cleanwhiteroom, vocals by elementals, guitar by elementals’ son, mastered by elementals as well, the brilliant and tirelessly patient.

Scientists discover what controls waking up and going to sleep

Fifteen years ago, an odd mutant fruit fly caught the attention and curiosity of Dr. Ravi Allada, a circadian rhythms expert at Northwestern University, leading the neuroscientist to recently discover how an animal’s biological clock wakes it up in the morning and puts it to sleep at night.

The clock’s mechanism, it turns out, is much like a light switch. In a study of brain circadian neurons that govern the daily sleep-wake cycle’s timing, Allada and his research team found that high sodium channel activity in these neurons during the day turn the cells on and ultimately awaken an animal, and high potassium channel activity at night turn them off, allowing the animal to sleep. Investigating further, the researchers were surprised to discover the same sleep-wake switch in both flies and mice.

“This suggests the underlying mechanism controlling our sleep-wake cycle is ancient,” said Allada, professor and chair of neurobiology in the Weinberg College of Arts and Sciences. He is the senior author of the study. “This oscillation mechanism appears to be conserved across several hundred million years of evolution. And if it’s in the mouse, it is likely in humans, too.”

Better understanding of this mechanism could lead to new drug targets to address sleep-wake trouble related to jet lag, shift work and other clock-induced problems. Eventually, it might be possible to reset a person’s internal clock to suit his or her situation.

The researchers call this a “bicycle” mechanism: two pedals that go up and down across a 24-hour day, conveying important time information to the neurons. That the researchers found the two pedals – a sodium current and potassium currents – active in both the simple fruit fly and the more complex mouse was unexpected.

The findings were published today in the Aug. 13 issue of the journal Cell.

“What is amazing is finding the same mechanism for sleep-wake cycle control in an insect and a mammal,” said Matthieu Flourakis, the lead author of the study. “Mice are nocturnal, and flies are diurnal, or active during the day, but their sleep-wake cycles are controlled in the same way.”

When he joined Allada’s team, Flourakis had wondered if the activity of the fruit fly’s circadian neurons changed with the time of day. With the help of Indira M. Raman, the Bill and Gayle Cook Professor in the department of neurobiology, he found very strong rhythms: The neurons fired a lot in the morning and very little in the evening.

The researchers next wanted to learn why. That’s when they discovered that when sodium current is high, the neurons fire more, awakening the animal, and when potassium current is high, the neurons quiet down, causing the animal to slumber. The balance between sodium and potassium currents controls the animal’s circadian rhythms.

Flourakis, Allada and their colleagues then wondered if such a process was present in an animal closer to humans. They studied a small region of the mouse brain that controls the animal’s circadian rhythms – the suprachiasmatic nucleus, made up of 20,000 neurons – and found the same mechanism there.

“Our starting point for this research was mutant flies missing a sodium channel who walked in a halting manner and had poor circadian rhythms,” Allada said. “It took a long time, but we were able to pull everything – genomics, genetics, behavior studies and electrical measurements of neuron activity – together in this paper, in a study of two species.

"Now, of course, we have more questions about what’s regulating this sleep-wake pathway, so there is more work to be done,” he said.

Year of Light: The problem of too much light

“For my part I know nothing with any certainty, but the sight of the stars makes me dream.” –Vincent Van Gogh

For the majority of human history, we have been able to step out into the night and observe the splendor of the universe with ease. Stars have guided the earliest navigators across tumultuous seas to discover new lands and have inspired many great works of literature and art. They are also a window to our universe with its mysteries and potential discoveries that await there as well.

Keep reading

Text messaging with smartphones triggers a new type of brain rhythm

Sending text messages on a smartphone can change the rhythm of brain waves, according to a new study published in Epilepsy & Behavior.  

People communicate increasingly via text messaging, though little is known on the neurological effects of smartphone use. To find out more about how our brains work during textual communication using smartphones, a team led by Mayo Clinic researcher William Tatum analyzed data from 129 patients. Their brain waves were monitored over a period of 16 months through electroencephalograms (EEGs) combined with video footage.

Dr. Tatum, professor of neurology and director of the epilepsy monitoring unit and epilepsy center at Mayo Clinic in Jacksonville, Florida found a unique ‘texting rhythm’ in approximately 1 in 5 patients who were using their smartphone to text message while having their brain waves monitored.

The researchers asked patients to perform activities such as message texting, finger tapping and audio cellular telephone use in addition to tests of attention and cognitive function. Only text messaging produced the newly observed brain rhythm, which was different than any previously described brain rhythm.

More information: William O. Tatum et al. Cortical processing during smartphone text messaging, Epilepsy & Behavior (2016). DOI: 10.1016/j.yebeh.2016.03.018

Credit: Elsevier