BioQuakes

AP Biology class blog for discussing current research in Biology

Author: gambinoacid

Brain Scans Suggesting Schizophrenia?

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On April 28, 2018

In Student Post

Schizophrenia is a mental disorder that usually starts between ages of 16 and 30. The symptoms vary from individual to individual, but common symptoms include hallucinations, delusions, and distorted perception. It is suspected usually in teens that have anxiety, depression, or sleep problems. However those symptoms do not always mean this teen has or will develop schizophrenia, usually only about ⅓ of these teens actually develop schizophrenia.

Researches now may have found a special “fingerprint” for the brain to determine if schizophrenia is likely before symptoms emerge. This “fingerprint” is really folds found within the brain. The method looks at MRI scans of the brain and the correlation between the amounts of folds in certain areas, reflecting the strength of connections in these areas. Researches composed an experiment to see how effective this method was at determining one’s likelihood of developing schizophrenia.

Photo Credit: Jurgitta (https://commons.wikimedia.org/wiki/File:Schizophrenia_brain_large.gif)

The research team collected MRI scans from a group of people in Switzerland, averaging the age of 24. The participants in this study included 79 people with suggestive symptoms of developing schizophrenia and 44 healthy control individuals. The researchers followed all of the participants for four years and found that 16 people in the high-risk group developed schizophrenia. After looking back through the brain scans, the researchers found that 80% of the time, the relationship between the folding patterns of the brain and the individuals who developed schizophrenia correlated. The individuals that developed schizophrenia brain scans seemed to have a “disorganized brain network”, meaning the folds of their cortical regions didn’t go hand in hand as much as the folds in the controls and the high-risk people who didn’t develop the illness. (The cortical regions of the brain refer to the cerebral cortex).

Although not yet perfected, this technique could be very useful in determining out of the individuals who have schizophrenia symptoms, their likelihood of actually developing this disorder.

CRISP New Technology: CRISPR

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On March 7, 2018

In Student Post

If you have ever seen GATTACA, and thought ‘Wow! I want to edit my genes!’… you may be in luck! CRISPR technology is a simple tool for editing ones genomes. (CRISPR is just a nickname for “CRISPR-Cas9”. ) A genome is an organism’s complete set of genes, including non-coding nucleic acid sequences. CRISPR technology has many different applications, including altering DNA sequences, modifying gene function, correcting genetic defects, and preventing the spread of diseases. Although all of these functions sound positive, CRISPR technology seems to raise ethical concerns.

 

DNA Pencil: Edit Photo By: mcmurryjulie

CRISPR stands for “clusters of regularly interspaced short palindromic repeats”, and is a specialized region of DNA with two definitive characteristics: the presence of nucleotide repeats and spacers. Nucleotides are the building blocks of DNA, and eventually proteins. CRISPR technology was adapted from the natural defensive mechanisms of bacteria. In order to repel attacks, these organisms use CRISPR derived RNA and various Cas proteins (including Cas 9), to attack foreign viruses, or other unknown bodies. CRISPRs are specialized stretches of DNA. The protein Cas9 is an enzyme that acts like a pair of “molecular scissors” which acts to cut strands of a person’s DNA. This protein usually binds to two RNA molecules: cRNA and another called tracrRNA. These two forms of RNA guide Cas9 to the target site, where it will make it’s “cut”. Cas9 cuts both strands of the DNA double helix, making what is known as a “double strand break”. This is how genes are editing.

Bouncing back to the defensive bacteria organisms that started this all, they attack foreign invaders by chopping up, and therefore destroying, the DNA. This allows for the manipulation of genes. These bacteria also use the spacers as a bank of memories which allows the bacteria to recognize viruses and other invaders.

However, due to these discoveries of how CRISPR technology works in bacteria, CRISPR technology is now going to be used to edit the genes of people to change genomes and possible diseases and phenotypes. This has caused some ethical concerns to arise in regards to CRISPR technology being used for human genome editing. Most of the changed involving genome editing are limited to somatic, or body cells, (not sperm or egg cells). Changes in body cells can’t be passed from generation to generation, but changes in sex cells can be passed onto future generations. Some of the previously mentioned ethical concerns include whether it would be a good idea to use this technology to enhance normal human traits (including height and intelligence). Due to these ethical concerns these genome edits are actually illegal in many countries!

The Science Behind Decision Making!

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On January 18, 2018

In Student Post

I consider myself, like most people, to be extremely indecisive. I also do not do very well when I find myself in stressful last minute decision making scenarios. A study done proves that it has to do with science!! According to a study done at Johns Hopkins University, it has been concluded that last-minute decision making and changing your mind is a complicated neural process involving complex neural coordination and communication among multiple brain areas.

Photo Credit: Affen Ajlfe (www.modup.net/)

 

Using functional magnetic resonance imaging, or fMRI, (a technique that monitors brain activity in real time), the research group found that changing your mind about a decision requires ultrafast communication between specific zones of the prefrontal cortex and a region of your brain called the frontal eye field. The frontal eye field is involved in controlling eye movements and visual awareness. The study found that the longer a decision takes to make, the longer it is held in the brain, and therefore the harder it is to reverse. This means that we are less likely to change our minds about a decision we have thought long and hard about.

Kitty Xu, the leader of experiment says  “If we change our mind about pressing the gas pedal even a few milliseconds after the original “go” message has been sent to our muscles, we simply can’t stop.  If we change our minds within roughly 100 milliseconds of making a decision, we can successfully revise our plans. If we wait more than 200 milliseconds, however, we may be unable to make the desired change—”. This finding is used to explain why sometimes, with age, adults are more likely to fall. As we age, our neural communicators slow which contributes to a message not reaching our muscles, or elsewhere fast enough to change our behavior.

The study’s next goal was to identify the brain regions involved in canceling a decision entirely. Participants took part in a fMRI and were instructed to watch a screen and stare at a black dot when it appeared. After focusing on the black dot, a colored dot would appear. The addition of a new stimulus caused the participants to abandon the original directed plan. The researchers watched on the fMRI which parts of the brain lit up during the decision making step to disregard the directions and look at the new dot. They found the prefrontal cortex and the frontal eye fields were the most active brain regions.

Xu hopes that these insights on how difficult it is for the brain to quickly change original plans can eventually lead researchers to find a way to lead us, specifically seniors, to safer decision making!

Need a Nap?

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On December 10, 2017

In Student Post

If you’re like me and enjoy soaking up the sun on a nice warm day, you may notice that after a little time in the sun… you’re ready for a nap! I sure know I am! I’ve always wondered why relaxing in the sun leads to feeling more exhausted than rejuvenated. Well here’s why!

Photo Taken by: Anthony Citrano www.zigzaglens.com (link to portfolio)

Our bodies are constantly working hard to maintain homeostasis, specifically temperature. On a warm day our bodies adjust to maintain this specific temperature. One way our bodies do this is through vasodilation. Vasodilation is the widening of blood vessels that result from the relaxation of muscular walls. This process allows for more blood to flow near the surface of your skin, allowing time for your blood to cool and release heat as it travels towards the skin’s surface. (If you ever find yourself over heated this increased blood flow near the skin explains why some people appear beet red when they’re hot)! Another way our bodies work to maintain homeostasis of body temperature is through sweat. When warm, our bodies secrete sweat onto our skin which then cools our skin as sweat evaporates!

But, in order for vasodilation and sweating to occur, our bodies have to do some work. Our heart and metabolic rates increase. It’s these occurrences that eventually lead to us feeling sleepy. Dehydration also plays a key role in fatigue. As your body secretes sweat, in attempts to cool down, you become more and more dehydrated.

Dehydration, when sun bathing, is also present if your skin gets burned or damaged. A sunburn is a sign that UV radiation has damaged the DNA in your skin cells. When you get sunburned, your body is constantly trying to repair the damage to those skin cells. One way the body attempts to repair the damage of a burn is diverting fluid from the rest of the body towards the burn leading to dehydration and therefore leading to fatigue.

In conclusion, as you soak up the rays wherever you may be, the best thing to do is to stay hydrated! Drink lots of non-diuretic beverages such as water and eat a salty snack! Non-diuretic beverages are those that keep you hydrated! Remaining hydrated will help somewhat with the fatigue you feel as you try and relax in the sun… what a paradox!!

Ladies…Put Down the Cheese and Pick up the Yogurt!

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On October 11, 2017

In Student Post

Diet has been known to play a key role in breast cancer risk. A study done by Karin B. Michels, professor and chair of the Department of Epidemiology at the Fielding School of Public Health at UCLA, at Medical News Today links a poor pro-inflammatory diet during adolescence, to a greater risk of developing breast cancer. A pro-inflammatory diet consists of foods such as red meats, butter, cheese, etc.  Because breast estrogenic hormones are found in these kinds of foods, researchers hypothesize that these compounds fuel breast cancer cell growth.

Photo taken by “kaboompics”: Karolina Grabowska

A case-control study, comparing breast cancer patients to women unaffected by the disease, by Roswell Park Cancer Institute also shows that there may be an association between types of dairy foods, specifically yogurt and cheese, consumed and breast cancer development.  Susan McCann, Professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park, says “dairy foods are complex mixtures of nutrients and non-nutrient substances that could be negatively and positively associated with breast cancer risk”. 

In the case-control study, scholars examined the association between the types of dairy food consumed among 1,941 women diagnosed with breast cancer between the years 2003-2014. Taking into account factors such as demographics, menopausal status, energy intake, and family history researchers found that women who consumed high amounts of yogurt were found to have a 39% lower risk of cancer development while women who consumed high amounts of cheese, particularly cheddar and cream cheese, had the opposite effect with a 53% increased risk of breast cancer. 

Connecting this case-control study to the study done with Medical News Today the results support the idea that a pro-inflammatory diet may cause a greater risk of developing breast cancer. Cheese is known to be part of the pro-inflammatory diet while yogurt is part of an anti-inflammatory diet.

Although more information is needed to definitely confirm these variables as a cause and effect, the correlation found provides us with more information about the possible causes of cancer. “This study of the differences among women and their consumption of dairy products offers significant new understanding into the potential risk factors associated with breast cancer. While diet is thought to be responsible for 30 percent of all cancers, we hope that further research will help us to more fully understand which food products are most valuable in terms of reducing risk for this disease.” (Senior author Christine Ambrosone: chair of the Department of Cancer Prevention and Control). 

As someone who has seen the impacts of breast cancer first hand, knowing all different correlational factors that may lead to the development of breast cancer is extremely important.

 

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