Sleep and Memory

Memory and learning occur in three stages: acquisition, consolidation and recall. 

Acquisition is the stage in which you learn and understand new information, whether this is the taste of your grandmother’s cookies or the steps to solve a quadratic equation. 

Consolidation is the step in which your brain stores the information, incorporating it into your existing knowledge and,

Recall is the step in which you access information and memories that have been stored.

When we sleep, our brains take the information that we have learned throughout the day and store it carefully in the neurons and cells that fill our brains. Slow wave sleep, which is the deep sleep during which we become rested, is particularly important to the consolidation process in processing and storing new facts. REM sleep, the deep sleep phase in which we dream, is when emotional memories are consolidated.

What happens to your memories if you are not getting enough deep sleep? Prior studies have found that we do not store memories as effectively and thus may have trouble recalling information, even with diligent study. 

However, many people feel that they must give up a certain amount of sleep in order to learn. After all, you cannot acquire information (or in scientific terms, go through memory acquisition) in your sleep, can you? According to new research, learning in your sleep may actually be a possibility.

Several prior studies have looked at whether it is possible to learn while you are asleep. Researchers in Germany, for example, gave study participants a group of Dutch words to study late at night. One group was then kept awake to continue studying, while the other slept while listening to the words play softly. When the sleeping group was awoken, both groups were given a test on the Dutch words they had learned. The people who slept scored higher

Many people think of sleep as nonproductive time, a simple biological necessity. However, there are several indications that it can be a valuable time for learning. When people are in deep slow-wave sleep, they produce a type of brain wave called theta waves, which are seen when we are awake and actively learning. We may be able to learn new foreign languages or a wide variety of new information if exposed to information in the right way while we sleep. These new studies suggest that being awake is not essential to learning and building memories.

In addition, sleep helps people to pay attention throughout their day, acquiring more information to be later consolidated in slumber. The health effects of sleeping well are also undeniable. If you want to perform and learn up to your best potential, missing sleep is not the answer.

https://www.chronobiology.com/learning-in-your-sleep-reality-or-just-a-dream/

Intermittent Fasting: More Than a Diet Fad

Fasting is one of the world’s oldest practices, used both for health and religious reasons over several millennia. Ascetics routinely gave up food and even water for days in search of meaningful change and insight. Intermittent fasting is slightly different from traditional fasting because people give up calories for shorter, well-defined periods of time. In the most popular type of intermittent fasting, users fast for 16 hours of the day and eat for the remaining eight.

The benefits of this style of eating are many, which is why it is steadily growing in popularity. People often lose dramatic amounts of weight, even when eating similar amounts of calories. Many people have seen their blood pressure and cholesterol lowered to safe and healthy levels. People with type 2 diabetes and other metabolic diseases also appear to have benefits. Even people who are otherwise healthy report positive health effects, such as increased energy, better sleep and improved digestive health.

How can simply changing the times when you eat have such dramatic health benefits? According to new research, the secret lies in the effects of intermittent fasting on the body’s internal clocks.

Our diet, especially the times when we eat, can affect our circadian rhythm in a variety of ways. Food stimulates insulin production, which in turn can activate different genes linked to internal clocks. In addition, eating stimulates our internal microbiome, the bacteria that live in our digestive tracts. These bacteria in turn release hormones and other biochemicals that can stimulate wakefulness or sleepiness.

According to new research, intermittent fasting may affect health and circadian clocks in more dramatic and previously unknown ways. Researchers looked at how periods of fasting affected mice.

Researchers divided mice into two groups: one that was placed on an intermittent fasting diet and one that had food available all the time. These mice ate the same amount of calories and fats. Despite this, the unrestricted eating group gained weight rapidly while the intermittent fasting group did not.

Muscle cells have two different modes to acquire energy. When glucose from food is readily available, insulin “unlocks” cell receptors so it can flood into muscle cells and power their activities. When glucose is in short supply, the liver produces ketones from fatty acids, which are then used to fuel muscle. Producing ketones causes a distinct shift in the metabolism of cells throughout the human body. Its effects on the circadian rhythm are particularly dramatic.

Mice who underwent intermittent fasting had larger oscillations in the activity of the genes that govern circadian rhythm. This means that they were biochemically primed to sleep better during their sleeping periods and were more wakeful during the day. Researchers believe that this is due to the effects of ketones on certain circadian genes. Regardless of the cause, it is apparent that intermittent fasting can lead to a stronger and more rhythmic circadian rhythm.

https://www.chronobiology.com/intermittent-fasting-affects-circadian-rhythm-says-new-study/

Exposure to LED lights could be harmful; scientists suggest a simple solution

In light of the harmful effects of radiations from LEDs, many manufacturers are taking a serious note and moving towards innovation.

Light emitting diode (LED) lights are becoming popular in India by the day as they are less expensive and more efficient. The Indian LED lighting market was worth US $3.7 billion in 2016 and the sector grew by 17.5 per cent between 2009 and 2016. But their health impacts have been largely out of public domain. 

In 2016, the American Medical Association (AMA) said that LED technology may impact human health. LED lights emit light from the short-wave, high-energy blue and violet end of the visible light spectrum. This light range controls our sleep cycle and correct exposure is important to maintain our circadian rhythm. Little wonder that many people complain of itchiness, redness in the eyes and mild headaches after continuous exposure to LED lights. The AMA says that life-long exposure of the retina and lens to blue peaks from LEDs can increase the risk of cataract and age-related macular degeneration. Studies also reveal that light emitted by LEDs can cause retinal changes, if there is high exposure for even a short period of time. 

A 2014 study published in Environmental Health Perspectives reported the adverse effects on the retina of rats due to chronic exposure to LED lights compared with other light sources that have less blue light. These researchers suggested a precautionary approach with regard to the use of blue-rich “white” LEDs for general lighting. Satya Karna, a consultant neuro-ophthalmologist with the Narayana Nethralaya, Bengaluru, says the lens and cornea have inherent ultraviolet light blocking, but with age some light, including blue peaks, can reach the retina and cause damage.

A study, which will be published in Vision Research in September this year, suggests that LED lights can cause headaches as they flicker too much. Compared to fluorescent lights which dim by around 35 per cent with every flicker, LED lights dim by 100 per cent. This can cause headaches by disrupting the movement control of the eyes, forcing the brain to work harder. 

Innovation at hand

Monto Mani, an associate professor at the Indian Institute of Science’s (IISc’s) Centre for Sustainable Technology in Bengaluru, had a tryst with LED lights not so long ago. “While working with fine artwork/tools under LED lights, my students complained of intense eye strain and a diminished clarity. On one occasion, while working under LED lights for about 20 minutes, I developed an uncharacteristic pain in the upper part of the eye (ball) which nearly lasted till the next morning. We then decided to find a solution to the problem,” says Mani.

Mani and his team tested most of the commercially available LED luminaire with a spectroradiometer and found the blue peak to be unnaturally high and very unlike the natural indoor light. Finally, through some quirk of intuition, Mani tested the lights after applying Kapton tape, a polyimide film that can remain stable across a wide range of temperatures. "To everyone’s delight, it did the job so well that one would even be convinced that these tapes were developed only to cut the blue peak. So much so, that our lab has all our LED lights with Kapton, and everyone who visits our lab feels that these lights feel good," says Mani.

In light of the harmful effects of these radiations, many manufacturers are taking a serious note of blue peaks from LEDs and are moving towards warmer LEDs without the blue peaks. Most warm LED lights, 4,000 K and even 2,700 K, still emit an uneasy blue peak, but are much subdued from the cool daylight 6,000 K variants. 

Experts recommend the blocking of blue light in the 415-455 nanometres (nm) spectrum in LED lighting for commercial use. Experimental evidence indicates that exposure to blue light in the range of 470–490 nm may be less damaging to the eye compared to blue light in the 400–460 nm range. Experts say that the development of LEDs with a peak emission of around 470–490 nm may represent an important advancement in the safety of LEDs for ocular health.

As LED lights are spreading rapidly in India, it is imperative to review their health impacts. This is also because many government programmes are pushing LED lighting, including the Union government’s Prakash Path programme, launched in January 2015 for efficient domestic lighting. There is a national programme for LED-based home and street lighting, and the Bureau of Energy Efficiency (BEE) too has launched a nationwide campaign under which LED lights will replace the incandescent bulbs to promote energy-efficient lighting. 

But for the common consumer, it may be wise to replicate Mani’s innovation. As he says, “We wanted to empower the common man with a simple and cost-effective DIY (do-it-yourself) technique to render the currently available lighting, as well as those who have already purchased and installed, safer for human (and wildlife) eyes.” IISc has, in fact, implemented Mani’s application for lighting up the campus and positive feedback is pouring in.

https://www.downtoearth.org.in/news/environment/exposure-to-led-lights-could-be-harmful-scientists-suggest-a-simple-solution-58544

International Symposium on Biological Rhythms organized by The Indian Society of Chronobiology

International Symposium on Biological Rhythms (in conjunction with the Biennial meeting of Indian Society for Chronobiology)
	Organised by Department of Zoology, Ch. Charan Singh University, Meerut & The Indian Society for Chronobiology (InSC) 11-13 March, 2019, Meerut, India

Convener: Professor Sanjay Kumar Bhardwaj

Broad Topics of the Workshop/ Symposium

• Biological clocks, ecosystem and conservation
• Genetic aspects of circadian and circannual timing
• Comparative Clocks
• Impact of ‘modern’ lifestyle in humans
• Cognition and behaviour
• Photoperiodism and Seasonality
• Sleep and its circadian relevance

For more details: http://chronobiologyindia.org/international-symposium/

TimeSignature as a new blood test to read internal clocks

One of the challenges in human circadian studies is tracking an individual’s own internal clock, which traditionally requires hourly sampling of markers such as melatonin across the 24-hour day, which is expensive and invasive for the subject. 

A new study published in the journal PNAS, has unveiled TimeSignature – a new software tool with the ability to estimate our biological time from just two blood draws, which can be flexibly spaced 8-12 hours apart. Rosemary Braun and colleagues measured the expression of thousands of genes in the blood from their own cohort of healthy volunteers, as well as from three other independent datasets already published. They then developed a machine-learning algorithm to sift through the data and make predictions of circadian time based on genes with the strongest cyclical patterns. 

The best markers consist of a panel of ~40 genes, many of which have diverse roles, such as in metabolism or immune function. This efficient new test is accurate to within 2 hours of an individual’s circadian time and will be useful in determining when our internal clock is out of sync with the time of the external world. As the blood test becomes clinically available, more easily than ever before will researchers and physicians be able to optimize the timing of medical interventions and explore the links between circadian disruption and chronic disease. 

Determining the state of an individual’s internal physiological clock has important implications for precision medicine, from diagnosing neurological disorders to optimizing drug delivery. To be useful, such a test must be accurate, minimally burdensome to the patient, and robust to differences in patient protocols, sample collection, and assay technologies. TimeSignature is a machine-learning approach to predict physiological time based on gene expression in human blood. A powerful feature is TimeSignature’s generalizability, enabling it to be applied to samples from disparate studies and yield highly accurate results despite systematic differences between the studies. This quality is unique among expression-based predictors and addresses a major challenge in the development of reliable and clinically useful biomarker tests. 

http://www.pnas.org/content/115/39/E9247

Know Thou Biological Clock monthly Newsletter - Maiden issue

KNOW THOU BIOLOGICAL CLOCK NEWSLETTER - Volume 1, Issue 1

(Saur Ashwin 1940 / Sept-Oct 2018)
______________________________________________________________________

Welcome to the Know Thou Biological Clock Newsletter

In this issue:

1.  Purpose
2.  About Institute of Chronobiology Education & Research
3.  Cutting edge Chronobiology Research
4.  Chronobiology in Ayurved – a perspective
5.  Site of the Month
6.  Chronobiology for Students
7.  Chronobiology for Professionals
8.  Tune your Clock – Games / Meditation Techniques
9.  Support ‘Know thou Biological Clock’ Newsletter
10. How to Stop Your Subscription

____________________________________________________________

From this month I will be writing a monthly newsletter both for academic and non-academic audience. The only purpose is to reach to the larger audience on regular basis with latest news in the field. I will publish only table of content on the blog.
Those interested can request the complete newsletter by sending email id to duraphe@gmail.com.

There is an opportunity of participating in the autorhythmometric (self circadian rhythm) analysis. By volunteering for the study, not only you will help generating scientific clinical data but also become aware about your own biological clock!
 
Following links will give you detailed information about the nature of the study and you can register in any or all of them. If you pass the eligibility criteria, then we will contact you with further instructions. 

Online Chronotype assessment

https://docs.google.com/forms/d/e/1FAIpQLSeiDNAKngayCtQ3M8Ab8wiCq-k84i6O0icb9LU-Ykn10brnJA/viewform?c=0&w=1

Online Sleep quality assessment

https://docs.google.com/forms/d/e/1FAIpQLSdK-ngtdFMmiSP093w2lHelyyTcL2I_9_82UL4Gjs_GdjdWtw/viewform?c=0&w=1

For volunteering in Autorhythmometry data collection and analysis please register at

https://docs.google.com/forms/d/e/1FAIpQLSfImnKLA8TM_9j_VuaeNrVHto5phPFWPDh70Rurb6RZGtfeLQ/viewform?c=0&w=1 

Chronotype Assessment

Online Chronotype assessment

Following questionnaire will assess your sleep-wake pattern and daily behavior so as to provide you the feedback about your chronotype or behavioral phenotype in scientific format.

The analysis will be useful for knowing and adjusting your disturbed biological clock. 

A disrupted biological clock is the root cause of all life style diseases whereas a normal biological clock is the key for sound health in the technology driven society.

Your response will be used for research purpose only and analysis report will be sent to you within one week on the email address provided by you.

Link for Chronotype questionnaire

https://docs.google.com/forms/d/e/1FAIpQLSeiDNAKngayCtQ3M8Ab8wiCq-k84i6O0icb9LU-Ykn10brnJA/viewform?c=0&w=1