Researchers at Northwestern University say we have a lot to learn about the link between sensory neurons and neurons controlling the sleep-wake cycle, but their findings are unlocking one piece of the puzzle.

In a study of the fruit fly, the researchers have identified a “thermometer” circuit that relays information about external cold temperature from the fly antenna to the higher brain. They show how, through this circuit, seasonally cold and dark conditions can inhibit neurons within the fly brain that promote activity and wakefulness, particularly in the morning.

“This helps explains why — for both flies and humans — it is so hard to wake up in the morning in winter,” said Marco Gallio, associate professor of neurobiology. “By studying behaviors in a fruit fly, we can better understand how and why temperature is so critical to regulating sleep.”

The paper describes for the first time “absolute cold” receptors residing in the fly antenna, which respond to temperature only below the fly’s “comfort zone” of approximately 77 degrees Fahrenheit. Having identified those neurons, the researchers followed them all the way to their targets within the brain. They found the main recipients of this information are a small group of brain neurons that are part of a larger network that controls rhythms of activity and sleep. When the cold circuit they discovered is active, the target cells, which normally are activated by morning light, are shut down.

Drosophila is a classic model system for circadian biology, the area in which researchers study the mechanisms controlling our 24-hour cycle of rest and activity. The focus of much current work is on how changes in external cues such as light and temperature impact rhythms of activity and sleep and how the cues reach the specific brain circuits that control these responses.

While detection of environmental temperature is critical for small “cold-blooded” fruit flies, humans are still creatures of comfort and are continually seeking ideal temperatures. Part of the reason humans seek optimal temperatures is that core and brain temperatures are intimately tied to the induction and maintenance of sleep. Seasonal changes in daylight and temperature are also tied to changes in sleep.

“Temperature sensing is one of the most fundamental sensory modalities,” said Gallio, whose group is one of only a few in the world that is systematically studying temperature sensing in fruit flies. “The principles we are finding in the fly brain — the logic and organization — may be the same all the way to humans. Whether fly or human, the sensory systems have to solve the same problems, so they often do it in the same ways.”

Source

If normal stress-busters such as exercise and distraction aren’t working, you may end up laying in bed staring at the ceiling … simply worrying rather than resting.  If you find that this is happening on a regular basis, you might try one more tactic — a worry journal.

Starting a worry journal is fairly easy. You sit down several hours before bedtime and write down what’s concerning you.  If you have ideas for solutions, maybe you could even write them as well.  Then, when it’s time to turn out the lights and go to bed, you close the book for the day and put it out of sight.

If this seems pretty simple, that’s because it is.  But, by giving an outlet to your stress and anxieties, you can hopefully get them out of your head long enough to get a good night’s rest.

Essentially, the research indicates that it’s better to either sleep or be active than sitting around all day.  Specifically, it found that substituting prolonged sedentary time with sleep was associated with lower stress, better mood and lower body mass index (BMI), and substituting light physical activity was associated with improved mood and lower BMI across the next year.

Jacob Meyer, lead author and assistant professor of kinesiology at Iowa State University, says light activity can include walking around your home office while talking on the phone or standing while preparing dinner.

“People may not even think about some of these activities as physical activity,” Meyer said. “Light activity is much lower intensity than going to the gym or walking to work, but taking these steps to break up long periods of sitting may have an impact.”

Getting more sleep is another relatively simple change to make. Instead of staying up late watching TV, going to bed earlier and getting up at a consistent time provides multiple benefits and allows your body to recover, Meyer said. Sleeping is also unique in that it is time you’re not engaging in other potentially problematic behaviors, such as eating junk food while sitting in front of a screen.

Making these subtle changes was associated with better current mood, but light physical activity also provided benefits for up to a year, the study found. While the research was conducted prior to the COVID-19 pandemic, Meyer says the results are timely given the growing mental health concerns during this time of physical distancing.

“With everything happening right now, this is one thing we can control or manage and it has the potential to help our mental health,” Meyer said.

Source

While we dream, we invent worlds that bear no relation to the quietness of our bedroom. In fact, it is rather unusual for elements of our immediate environment to be incorporated into our dreams. To better understand how the brain protects itself from outside influences, researchers invited 18 participants to a morning nap in the lab. Morning sleep is rich in dreams. Dreams mostly occur during what is known as REM sleep, since the brain is somehow in a waking state during this phase of sleep, showing brain activity similar to that when a person is awake. The body, on the other hand, is paralyzed, although not entirely. During certain phases of REM sleep, the eyes continue to move. Research has shown that such movements are related to dreaming.

To study how the dreaming brain interacts with external sounds, the scientists got volunteer sleepers to listen to stories in French mixed with meaningless language. By combining the electroencephalogram with a machine learning technique, they confirmed that, even when the brain is asleep, it continues to record everything that goes on around it (2). They also showed that, during light sleep, the brain prioritizes meaningful speech, just as it does when in the waking state. However, such speech is actively filtered out during eye movement phases in REM sleep. In other words, our sleeping brain can select information from the outside world and flexibly amplify or suppress it, depending on whether or not it is immersed in a dream!

The team believe that this mechanism enables the brain to protect the dreaming phase, which is necessary for emotional balance and consolidation of the day’s learning. Although dreams are predominant during periods of eye movement, they can also occur during other phases of sleep. Are they then accompanied by a similar suppression of sensations from the outside world?

Source

As the days are getting warmer, the change of seasons is a golden opportunity to take a look at how making some changes can make a big difference in your nightly rest.

Here are our Top Five Spring Cleaning Sleep Tips:

• Ditch the flannel pajamas.  If you haven’t already, it’s probably time to swap your winter sleep clothes for more summery material. The light fabric should make you feel like you’re not sleeping under a ton of material, and being too hot makes it hard to stay asleep during the night.
• Have you aired out the house since winter? In some areas of the United States, we go straight from running the heat all the time to running the air conditioning.  On the next nice  day, open the windows during the day to let some fresh air into the house.
• Are you an allergy sufferer? Make sure your pillows and mattress are clean and that your pillows have been switched out recently so you are not affected by an overabundance of allergens like dust mites, dust, and old skin cells on your pillow. You might also consider a hypoallergenic pillow.
• Use the right kind of blanket. A breathable blanket can make a huge difference in your sleep comfort. Try a few different blankets to see which gives you the best sleep quality.
• Keep your schedule.  The transition to longer days with more sunshine can cause a sleep schedule disruption for some people. Resist the urge to stay up later and keep to your normal bedtime.

Each season brings different sleep challenges. With a little effort you can get a great return on how much and how well you sleep. And, since the quality of your sleep affects all other aspects of your life, it’s worth the time to take a few moments to review your sleeping arrangements.

During sleep, the brain replays neural firing patterns experienced while awake, also known as “offline replay.” Replay is thought to underlie memory consolidation, the process by which recent memories acquire more permanence in their neural representation. Scientists have previously observed replay in animals, but the study tested whether the phenomenon happens in human brains as well.

The team asked the two participants to take a nap before and after playing a sequence-copying game, which is similar to the 1980s game Simon. Instead of moving their arms, the participants played the game with their minds — imagining moving the cursor with their hands to different targets one by one, hitting the correct colors in the correct order as quickly as possible. While the participants rested, played the game, and then rested again, the researchers recorded the spiking activity of large groups of individual neurons in their brains through an implanted multi-electrode array.

“There aren’t a lot of scenarios in which a person would have a multi-electrode array placed in their brain, where the electrodes are tiny enough to be able to detect the firing activity of individual neurons,” says co-first author Beata Jarosiewicz. Electrodes approved for medical indications, like those for treating Parkinson’s disease or epilepsy, are too big to track the spiking activity of single neurons. But the electrode arrays used in the BrainGate pilot clinical trials are the first to allow for such detailed neural recordings in the human brain. “That’s why this study is unprecedented,” she says.

BrainGate is an academic research consortium spanning Brown University, Massachusetts General Hospital, Case Western Reserve University, and Stanford University. Researchers at BrainGate are working to develop chronically implanted brain-computer interfaces to help people with severe motor disabilities regain communication and control by using their brain signals to move computer cursors, robotic arms, and other assistive devices.

In this study, the team observed the same neuronal firing patterns during both the gaming period and the post-game rest period. In other words, it’s as though the participants kept playing the Simon game after they were asleep, replaying the same patterns in their brain at a neuronal level. The findings provided direct evidence of learning-related replay in the human brain.

“This is the first piece of direct evidence that in humans, we also see replay during rest following learning that might help to consolidate those memories,” said Jarosiewicz. “All the replay-related memory consolidation mechanisms that we’ve studied in animals for all these decades might actually generalize to humans as well.”

The findings also open up more questions and future topics of study who want to understand the underlying mechanism by which replay enables memory consolidation. The next step is to find evidence that replay actually has a causal role in the memory consolidation process. One way to do that would be to test whether there’s a relationship between the strength of the replay and the strength of post-nap memory recall.

Although scientists don’t fully understand how learning and memory consolidation work, a cascade of animal and human studies has shown that sleep plays a vital role. Getting a good night’s sleep “before a test and before important interviews” is beneficial for good cognitive performance, said Jarosiewicz. “We have good scientific evidence that sleep is very important in these processes.”

Source

Negative mood is not unusual in adolescence, but lack of sleep can affect mental health, causing anhedonia (or loss of pleasure), anxiety, anger and significantly increasing the risk of depression, a global study of more than 350,000 teens shows.  The results connect less sleep with a 55% increased chance of mood deficits and double the risk of reduced positive mood.

From Asia, to Australia, New Zealand, Europe and North America, sleep clearly was a modifiable risk factor that can improve or depress mood in adolescents, says Flinders University sleep researcher Dr Michelle Short.

“Sleep duration significantly predicts mood deficits on all mood states, including increased depression, anxiety, anger, negative affect and reduced positive affect,” she says, with less sleep linked to an 83% higher chance or anger, 62% increased risk of depressed mood, and 41% higher risk of anxiety.

“Fortunately, there are many interventions individuals, family, the community and even public policy can encourage to maintain regular sleep in this at-risk population to reduce the likelihood of these problems spilling over into mental health issues needing clinical treatment,” she says.

The researchers also recommend increased parental / guardian regulation of sleep and technology use, delayed school starting times, and monitoring academic and other pressures such as out-of-hours tutoring does not impede sleep routine.

Dr Short says that “while positive mood doesn’t get much attention, it is still clinically relevant as one of the key symptoms of depression in anhedonia (loss of pleasure).”

“It is imperative that greater focus is given to sleep as for prevention and early intervention for mood deficits,” the study concludes.

Source

1. Take a shower. Try taking a shower right before bed.  It will wash the pollen out of your hair and off of your body, making for a more pollen-free bed.
2. Vacuum and wash your sheets. This time of year, many people (understandably) want to open the windows and air out the house.  Unfortunately when you do that, you’re letting in the very thing that’s making you sneeze.  Try running a vacuum in your bedroom each night, and wash your sheets more frequently than usual.
3. Use newer allergy medications. The newer allergy medicines like Claritin, Zertec and Allegra don’t generally interfere with your sleep.  If possible, avoid the versions of these medications that have a “D” by their name, as they include pseudoephedrine, a medicine that does tend to either make people sleepy or wake them up.
4. Don’t reach for the Benadryl. Benadryl is a strong antihistamine that many people use to treat allergies. It also has the side effect of making you very sleepy. It works so well in making people sleepy, in fact, that some find they can no longer fall asleep without it.  It’s best not to start down that road unless directed by a doctor.
5. Wash out your sinuses.  Use a Neti Pot or any number of other over-the-counter sinus rinse solutions each night to help keep as much of the allergy-causing particles out of your sinus passages, and also help remove excess mucous.  During the day, a saline nasal spray is a good solution.

In the end, for most people at least, the spring allergy season lasts only a few weeks to a month.  If you can make it through that time without becoming severely sleep deprived, you’ll find that your nose and head are clearer as we head into summer.

“The 2020 State of America’s Sleep” study was conducted by The Better Sleep Council (BSC), the consumer education arm of the International Sleep Products Association (ISPA).  Here are some of the key findings that relate directly to sleep:

• In January 2020, 54% of Americans were getting the minimum 7-8 hours of recommended sleep. As of March, fewer than half (49%) did.
• Similarly, in January 2020, over four in 10 Americans described their sleep as poor or fair (43%). As of March, over half of the nation qualified their sleep as poor or fair (52%).
• While about three in 10 Americans woke up feeling rested and refreshed often or frequently before COVID-19 (30% in January 2020), only 2.4 in 10 Americans (24%) did as of March.
• Negative posts on social media relative to sleep jumped from 45% of all sleep-related posts to 73% in March compared to last year.

Also included in the survey were some questions about things that could cause Americans to lose sleep:

• In January 2020, four in 10 (41%) Americans reported feeling stressed often or very often. As of March, over half Americans (53%) felt stressed about COVID-19 often or very often.
• About one-third of the nation felt good about the economy in January 2020 (38%) vs. less than 20% did as of March 2020.
• Lack of confidence in the stock market prevailed in the nation in March (56% of Americans disagree that they have confidence in the stock market vs. 39% in January 2020).

“It’s no surprise that COVID-19 negatively impacted Americans’ health and the extreme two-month sleep shift is alarming,” said Mary Helen Rogers, vice president of marketing and communications for the Better Sleep Council. “However, if we take our findings and help Americans unwind and sleep better during this pandemic, we’ll fulfill our role as the Guardians of America’s Sleep.”

But a new study published this week found that the direction of this reaction might actually be flipped: It’s not the sleep loss that leads to obesity, but rather that excess weight can cause poor sleep, according to researchers from the University of Pennsylvania’s Perelman School of Medicine and the University of Nevada, Reno, who discovered their findings in the microscopic worm Caenorhabditis elegans (C. elegans).

“We think that sleep is a function of the body trying to conserve energy in a setting where energetic levels are going down. Our findings suggest that if you were to fast for a day, we would predict you might get sleepy because your energetic stores would be depleted,” said study co-author David Raizen, MD, PhD, an associate professor of Neurology and member of the Chronobiology and Sleep Institute at Penn.

Raizen emphasized that while these findings in worms may not translate directly to humans, C. elegans offer a surprisingly good model for studying mammalian slumber. Like all other animals that have nervous systems, they need sleep. But unlike humans, who have complex neural circuitry and are difficult to study, a C. elegans has only 302 neurons — one of which scientists know for certain is a sleep regulator.

In humans, acute sleep disruption can result in increased appetite and insulin resistance, and people who chronically get fewer than six hours of sleep per night are more likely be obese and diabetic. Moreover, starvation in humans, rats, fruit flies, and worms has been shown to affect sleep, indicating that it is regulated, at least in part, by nutrient availability. However, the ways in which sleeping and eating work in tandem has remained unclear.

“We wanted to know, what is sleep actually doing? Short sleep and other chronic conditions, like diabetes, are linked, but it’s just an association. It’s not clear if short sleep is causing the propensity for obesity, or that the obesity, perhaps, causes the propensity for short sleep,” said study co-author Alexander van der Linden, PhD, an associate professor of Biology at the University of Nevada, Reno.

To study the association between metabolism and sleep, the researchers genetically modified C. elegans to “turn off” a neuron that controls sleep. These worms could still eat, breathe, and reproduce, but they lost their ability to sleep. With this neuron turned off, the researchers saw a severe drop in adenosine triphosphate (ATP) levels, which is the body’s energy currency.

“That suggests that sleep is an attempt to conserve energy; it’s not actually causing the loss of energy,” Raizen explained.  “There is a common, over-arching sentiment in the sleep field that sleep is all about the brain, or the nerve cells, and our work suggests that this isn’t necessarily true.  There is some complex interaction between the brain and the rest of the body that connects to sleep regulation.”

Source