Tag Archives: Physiology

Scientists find universal law of nature that may govern all living things

Imagine walking out of the subway onto a busy street or going to a loud concert with flashing lights. At first, you’re highly stimulated by the roar of the bustling street or the strobe lights, but then you naturally get used to it. Without this adaptive ability, we’d all go mad, especially considering the number of stimuli we’re bombarded with on a daily basis. And it’s not just humans either. It could be that all organisms follow the same physiological adaptation curve, governed by a universal law of physiology recently uncovered by researchers at the University of Toronto.

Professor Willy Wong. Credit: Matthew Tierney / University of Toronto Engineering.

The team of researchers who came across this universal relationship of physiology was led by Prof. Willy Wong. Although the findings have huge implications for biology, Wong is actually a professor of biomedical and computer engineering. Previously, he made important contributions to brain-machine interfaces, such as devising a retinal prosthesis that restores partial vision to blind patients.

It was this work at the interface between senses and the brain that eventually led him down a rabbit hole where he noticed our response to different stimuli follows a surprisingly similar curve. And it all seems to be owed to how neurons communicate.

In order to communicate with one another, neurons fire a nerve impulse known as an action potential. This action potential, which always fires at the same intensity, is activated only once a certain threshold is reached.

“Action potentials don’t come in half measures,” says Wong. “Either you get one or you don’t. If you do, the neuron needs some time to recharge before it can fire another. In adaptation, the rate of action potential generation falls gradually to some non-zero steady state.”

In their new study, Wong and colleagues compared 250 measurements of adaptation from different fields of sensory psychology and found they all converged to a single equation. This very simple equation describes the adaptation response in all animals, from vertebrates like mammals to invertebrates like insects, and is valid for all five senses: vision, hearing, touch, taste, and smell.

The equation can be stated as the steady-state response (SS) equals the square root of the product between the activity before the application of the stimulus (SR) and the peak activity that occurs at the first presentation of the stimulus (PR). In visual format, this equation describes a curve that instantly rises when we encounter a new stimulus, but then steadily tapers off until we reach a new equilibrium.

Graph showing the idealized sensory adaptation response. Credit: Willy Wong.

The equation applies to virtually all living things, including jelliyfish, which are some of the oldest multicellular organisms.

“If you shine a light on them, they either fly to the light or away from it—but only because their photoreceptors are hardwired to their motor output,” he says. “Which raises the question, is this equation universal? In the future, if we find aliens with exobiology never seen on this planet, could they also be constrained by the same limitations or principles?”

The findings are based on data from hundreds of unrelated independent studies, which used different methods and were performed across different time periods spanning decades. Although this is by no means absolute proof, the unified nature of this research strengthens the notion that all things process stimuli according to a universal law.

“All this data was there,” says Wong, “All conformed to the same geometric mean relationship. It’s not dependent on the researcher, on what equipment was used, or on the organism. From that perspective, it is universal.”

The study was published this week in the journal Frontiers in Human Neuroscience.

Nobel Prize for Medicine awarded for circadian rhythm research

Jeffrey C. Hall, Michael Rosbash and Michael W. Young have been awarded the 2017 Nobel Prize in physiology or medicine for their work on molecular mechanisms controlling circadian systems.

It’s my favorite kind of research: sleep research. Circadian rhythms control when we’re at our best, our worst, and when we sleep. For everything we do that messes up this rhythm, we pay a price. Fly to a different time zone? Jet lag. Midnight snack? Mess up your metabolism. All nighter? Feel like crap the next day. The circadian rhythm affects everything from energy levels to metabolism, mood, and even fertility. But how is our body so good at keeping time, and how do all the individual parts of our body keep the same rhythm?

“The circadian system has its tentacles around everything,” Rosbash said in an interview with the HMI Bulletin in 2014. “It’s ticking away in almost every tissue in the human body.” It’s also in plants, including major food crops, the article noted, and appears to be tied to “disease susceptibility, growth rate, and fruit size.”

This is where the research steps in. The field of science emerged in the 1970s when geneticist Seymour Benzer and his student Ron Konopka managed to track down the genes that encode biological timing in fruit flies. Hall, Rosbash and Young also studied fruit flies, using them as a model organism. They showed that many genetical abnormalities and serious diseases are correlated with irregular circadian rhythms. A genetic mutation has already been found in some people who have a chronic sleeping problem, Young said. Among others, Alzheimer’s, depression, attention-deficit/hyperactivity disorder (ADHD), heart disease, obesity and diabetes and other metabolic issues are all included.

They suspected that because the effects are virtually ubiquitous inside the body, the brain likely uses one element to keep track of time. It wasn’t easy, but they managed to isolate a gene that is responsible for a protein that accumulates in the night but is degraded in the day. This was one of the key cogs in the mechanism, and paved the way for their later groundbreaking research.

“Before you’ve got the genes, everything is a black box,” Michael Hastings of the MRC Laboratory of Molecular Biology in Cambridge, England, said. “Once you’ve got the genes, everything is possible.”

At the moment, the discovery didn’t generate the excitement it probably deserved. Even though researchers explained that it could one day enable us to understand sleep and the circadian rhythm, it just didn’t cause a big stir. It took years and years before the doors their research opened became obvious.

Hall, who is now retired, said he got the notice call at 5 a.m. — but due to age-related changes in his own circadian rhythms, he was already awake. He added that he would love to reinvest some of the money into his research… but unfortunately, he retired from that years ago.Here’s his awesome and unconventional speech:

 

Rosbash, a 73-year-old professor at Brandeis, talked more about their research. He told the AP that he and his two colleagues worked to understand “the watch … that keeps time in our brains.”

“You recognize circadian rhythms by the fact that you get sleepy at 10 or 11 at night, you wake up automatically at 7 in the morning, you have a dip in your alertness in the midday, maybe at 3 or 4 in the afternoon when you need a cup of coffee, so that is the clock,” he explained.

“The fact that you go to the bathroom at a particular time of day, the fact if you travel over multiple time zones your body is screwed up for several days until you readjust — all that is a manifestation of your circadian clock.”

The Nobel Prize in Physics was also awarded earlier today. I won’t give any spoilers, but the gravity of the situation should not be underestimated.

2015 Nobel prize for Physiology or Medicine Awarded

This year’s Nobel Prize in Physiology or Medicine is split into three parts, being divided between William C. Campbell and Satoshi Ōmura — who jointly share a half “for their discoveries concerning a novel therapy against infections caused by roundworm parasites” — and Youyou Tu “for her discoveries concerning a novel therapy against Malaria.”

Image via wattsupwiththat

 

Alfred Nobel had an active interest in all areas of research, including medicine. In his will, he set for the Prize to be awarded each year for scientific excellence in five major fields of study: Physics, Chemistry, Physiology or Medicine, and Economic Sciences.

The Physiology and Medicine part of the Nobel prize is awardied by the Nobel Assembly at Karolinska Institutet in Stockholm, Sweden, for discovery of major importance in life science or medicine. Discoveries that have changed the scientific paradigm and are of great benefit for mankind are awarded the prize, whereas life time achievements or scientific leadership cannot be considered for the Nobel Prize.

A total of 327 scientists have been nominated for the 2015 Nobel Prize in Physiology or Medicine, among who 57 individuals were nominated for the first time. This year it was claimed by the guys studying the bugs, for research into the treatment of roundworm parasite infections and Malaria.

The winners of the Nobel Medicine prize 2015 (L-R) Irish-born William C Campbell, Satoshi Omura of Japan and China’s Youyou Tu. Photograph credits to: Jonathan Nackstrand

The winners of the Nobel Medicine prize 2015 (L-R) Irish-born William C Campbell, Satoshi Omura of Japan and China’s Youyou Tu.
Photograph credits to: Jonathan Nackstrand

 

William C. Campbell and Satoshi Ōmura discovered a new drug, Avermectin, the derivatives of which have radically lowered the incidence of River Blindness and Lymphatic Filariasis, as well as showing efficacy against an expanding number of other parasitic diseases. Youyou Tu discovered Artemisinin, a drug that has significantly reduced the mortality rates for patients suffering from Malaria.

Campbell’s and Ōmura’s Ivermectin is currently seeing use in all parts of the world that are plagued from parasitic diseases, invaluable for improving the wellbeing of millions of people with River Blindness and Lymphatic Filariasis, primarily in the poorest regions of the world. It’s so effective, in fact, that the diseases are on the verge of eradication, a major feat of medical history.

Artemisinin is used in all Malaria-ridden parts of the world, and with 200 million individuals who report infection with the disease each year, it’s seeing a lot of use. When used in combination therapy, it is estimated to reduce mortality from Malaria by more than 20% overall and by more than 30% in children. For Africa alone, this means that more than 100 000 lives are saved each year.

“The discoveries of Avermectin and Artemisinin have revolutionized therapy for patients suffering from devastating parasitic diseases. Campbell, Ōmura and Tu have transformed the treatment of parasitic diseases. The global impact of their discoveries and the resulting benefit to mankind are immeasurable,” Karolinska Institutet’s award decision reads.