BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: muscle

The Fountain of Youth for Muscles: Targeting 15-PGDH to Halt Age-Related Weakness

Eventually, everybody ages. While some good things come with age, aspects of aging, such as muscle weakness, can now potentially be stopped. For a long time, scientists have wondered why muscles start to weaken as humans age, but now, due to a recent ScienceNews article, we may be able to answer and solve muscle weakness!

Muscle Tissue: Cross Section Whole Skeletal Muscle

In the article, scientists discovered that inhibition of an an enzyme called 15-hydroxyprostaglandin dehydrogenase, or 15-PGDH for short, can help with strength and more muscle mass in older humans. 15-PGDH breaks down a signaling compound called prostaglandin E2, which activates the production of muscle cells that regenerate damaged muscles. Though it may seem confusing why 15-PGDH breaks down prostaglandin, the enzyme is a tumor suppressor. The enzyme inhibits proliferation so that cancer and other cells can be differentiated. In younger muscle tissue, 15-PGDH was found at reduced and relatively little abundance, but in older muscle fibers, it was found in great abundance, which caused relatively minor muscle repair. In the study, 15-PGDH was inhibited by gene knockout. However, studies show that the enzyme has potential effectors that cause an induced closure of the enzyme’s active site, which inhibits 15-PGDH. This would be an allosteric interaction in which the effector works by binding to the enzyme and changing the shape of the active site so that it can no longer work.

Silence of the Genes

Eventually, everybody ages, so this discovery is important to me. Being able to have optimal strength and energy while being old may be possible, according to the findings made by scientists. Hopefully, by the time I age, these findings can help allow older humans to continue to have peak performance. If you guys have any other studies relating to human muscle deterioration, I would love it if you shared them in the comments!

 

You’re a Jerk!!!

Have you ever woken up in the middle of the night because you felt like you were falling?? What about waking up from sudden muscle spasms you’ve experienced in your sleep?? If you answered yes to either or both questions, that means you’ve experienced a hypnagogic jerk!

A term referencing to the period between wakefulness and sleep, called the hypnagogic state, hypnagogic jerks are involuntary muscle spasms that occur during light sleeping. These jerks are also known as ‘sleep starts’ and effect 70% of the population. Some factors scientists know to cause and increase the amount of twitches one can experience are high caffeine intake, stress, fatigue, anxiety, sleep deprivation, and intense activity and exercise right before sleep. Additionally, it is surmised that these spasms can also be induced by sound, light, and other external factors.

In a recent study, different people have reported that with these jerks comes hallucinations, vivid dreams, or even ringing noises inside of their heads! Though, with the acknowledgement of hypnagogic jerks and what comes with them, the actual main cause in the body is unknown. Here are two popular theories from the researches:

  1. The first idea is that the jerks are just natural when transitioning from alertness to sleep by nerves in the body ‘misfiring’.
  2. The second idea is that hypnagogic jerks result from evolution. It’s argued that the spasms are a primitive reflex where the brain at one time in history misinterpreted the transition from movement to relaxation and sleep as a sign of the primate falling, making the muscles quickly react.

Even with those two theories the actual cause is still a mystery and scientists continue to try and find it. Though don’t be scared if you experience a hypnagogic jerk once in a while that causes you to wake up, but if this starts to happen on a more frequent and repetitive basis seek a sleep specialist!

Feel free to comment your experiences with hypnagogic jerks!!

Original Source: https://www.livescience.com/39225-why-people-twitch-falling-asleep.html

Biologists grow real human muscle

Scientists at Duke University recently announced that they have successfully bioengineered a human muscle that expands and contracts just like the real thing. Scientists see vast opportunities for this new advancement. It could become a powerful tool for studying diseases like muscular dystrophy. Not only could it help understand these diseases, but the engineered muscle could help scientists develop drugs to treat these diseases without the need to test on human beings. Dr. Grace Pavlath, senior vice-president and scientific program director for the Muscular Dystrophy Association,  says that the discovery will most benefit from testing cures to diseases without the risk of human life.

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To create the muscle, the scientists extracted special muscle “precursor” cells from human bodies and then multiplied then up to 1,000 times. Then they mixed the cells with a special gel and placed it in a 3d mold, which stimulated the growth of this muscle. When they stimulated the muscle with electric shocks and a number of different drugs, the scientists were delighted to find that the muscle reacted just like human tissue would, contracting and expanding as the impulses hit the muscle. This breakthrough holds large implications for improving research and testing of cures to many muscular diseases.

 

Source: http://www.huffingtonpost.com/2015/01/15/lab-grown-muscle-first-contracting_n_6471398.html?utm_hp_ref=science

Pull-Ups, Biology, and Our Sexist Society

Men and women are different, right? Guys have more testosterone, which leads to greater muscle mass, facial hair, deeper voice, and greater height. Women have more estrogen, which leads to the development of characteristics like wider hips, and breast development. Having less testosterone means it is harder to gain strength, but not impossible. Anyone can, with the proper training regimen  increase their strength, regardless of sex. This, however, goes against what New York Times writer Tara Parker-Pope writes in her article Why Women Can’t Do Pull-Ups. In it, she cites a study in which

 Three days a week for three months, the women focused on exercises that would strengthen the biceps and the latissimus dorsi — the large back muscle that is activated during the exercise. They lifted weights and used an incline to practice a modified pull-up, raising themselves up to a bar, over and over, in hopes of strengthening the muscles they would use to perform the real thing. They also focused on aerobic training to lower body fat.

According to the study, only four of the seventeen women were able to do one pull-up at the end of the study. I, along with several hundreds of people who have posted angry comments on this article, have several issues with this study, and with the title of the article.

First, they focused on exercises that would strengthen the biceps and latissimus dorsi. My question is, what about the deltoids and trapezius muscles, and the core muscles in the abdomen, and grip strength? All of these come into play to some extent in a pull-up.

Second, I know from personal experience that using an incline to work your way up to pull-ups, often called a supine row, does not work.  I tried this for months and still could not do a pull-up. What did work was jumping over the bar and lower myself slowly (this is called negatives), and using resistance bands to hold whatever weight I could not support while doing a full pull-up. Now, I can do pull-ups. And, when you really think about it, a supine row uses the same muscles but the movement is in no way similar, so it doesn’t make sense to see it as a “toned-down” pull-up for beginners.

Taken by Amber Karnes
http://www.flickr.com/photos/ambernussbaum/4472515271/
2010 CrossFit Games; Women did pull-ups with a 14 lb vest.

Third, how in shape were these women? This was not made clear in the article, and obviously, even after six months to a year, a morbidly obese woman may not be able to do a pull-up.  I think the issue with the study and the article comes down to two things: bad journalism and bad science.  When a 17 year old AP Biology student is able to poke a bunch of holes in your argument and find a bunch of flaws in your experimental procedure, the competence of the individuals involved comes into serious question.

So, readers, can YOU do a pull-up? Do you know any females that can do pull-ups? And, if you were to run the experiment, what would you do differently?

Comment!

Original Article:

http://well.blogs.nytimes.com/2012/10/25/why-women-cant-do-pull-ups/

 

Additional Information:

http://en.wikipedia.org/wiki/Supine_row

http://en.wikipedia.org/wiki/Pull-up_(exercise)#Muscles_used

 

Photo: http://www.flickr.com/photos/ambernussbaum/4472515271/

What CAN’T Exercise Do?!

As I’m sure you’re all well aware, exercise makes you stronger. This is because exercise increases the amount of muscle mitochondria and basically the more mitochondria you have in your muscle cells, the more durable and fatigue-resistant (strong) your muscles are.

Credit: PictureYouth Flickr

Well guess what? You’re brain is a muscle too.

Studies show that brain cells are also fueled by mitochondria, and therefore also get stronger through working out. This is because “the brain has to work hard to keep the muscles moving” (J. Mark Davis, University of South Carolina Professor).

J. Mark Davis and his fellow scientists at the Arnold School of Public Health at the University of South Carolina conducted a test with mice for 8 weeks to figure out how this actually works. There was one group of mice that exercised every day, and one group that just lounged around. At the end of 8 weeks, the group that exercised performed extremely well on an endurance test and had a huge surge of “newborn mitochondria” in their brain cells. Of course no improvement was seen for the lounging mice, because they were lazy and didn’t exercise!

This is extremely good news, especially for neurologists studying Alzheimer’s and Parkinson’s disease, which are believed to be caused by mitochondria deficiencies in human brain cells.

Credit: Jules.K. Flickr

But the benefits don’t stop there! By working out, you are decreasing bodily or mental fatigue. That’s why the more you work out, the longer you can spend working out. Also, by decreasing mental fatigue, you’re making your brain sharper.

So the next time you stay up all night studying for your AP Bio test, don’t forget to take a casual 30-minute jog or just do some yoga. It will really help (plus it’s always good to take a break from studying)!

For more information about the benefits of exercise, please visit the following site.

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