BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: depression

Metagenomics will stare into your soul… and beyond?

If you ever feel lonely, take solace in the fact that at any given time there are thousands of bacteria cells living in your gut, (inside your skin!).

As it turns out, there’s a whole lot of ‘not you‘, living in you.

Admittedly, they don’t make the best company as they tend to be on the quieter side.

They make up for it by being fantastic listeners.

Improving Human Intestinal Health

https://www.flickr.com/photos/pnnl/8146322408

Courtesy of Pacific Northwest National Laboratory.

They also serve as an essential part of our bodily systems, referred to by Valeria D’argenio in her essay The role of the gut microbiome in the healthy adult statusas “our forgotten organ”.

One great measure of how important something is is how wrong things go when the original thing isn’t doing it’s thing properly. Put eloquently by D’argenio “Quantitative and qualitative alterations in the composition of the gut microbiome could lead to pathological dysbiosis, and have been related to an increasing number of intestinal and extra-intestinal diseases”. The Human Gut micro biome is important to maintaining good health. Interestingly though (and somewhat alarmingly), the human gut micro biome has historically been fairly hard to study. as D’argenio puts it “microbial studies were based on the direct cultivation and isolation of microbes” and then later states that “it is estimated that up to 99% of microbes are currently uncultivable”. These facts make it clear that with old methods, the human gut micro biome has been extremely hard to study effectively. Which is crazy because the human gut micro biome is so important. Metagenomics are changing the game.

Recently new strategies  known as Metagenomics have been discovered that avoid the inefficient and ineffective cultivation step. Using the “Shotgun Sequencing” strategy, scientists have become able to sequence the DNA directly and have gained the ability to sequence entire microbial communities. This new method represents a significant step in understanding the human but microbiome but it is not perfect. D’argenio references limitations to current DNA sequence databases and difficulty in deciphering DNA function as obstacles that have yet to be totally overcome.

16s rRNA Sequencing is another form of metagenomics helping to illuminate the mysteries of the human gut micro biome. All bacteria contain the 16s rRNA. The 16s rRNA Sequencing gene takes advantage of this fact by identifying this gene in a large sequence and gaining a clearer view of which bacteria species are present in certain environments. This strategy is cost effective and can be performed rapidly but offers no insight as to bacterial function.

Metatranscriptomics succeeds where 16s rRNA Sequencing fails. In the words of D’argenio “Metatranscriptomics serves to analyze the entire transcriptome of an environmental site to obtain a comprehensive view of gene expression profiles and functional data”. Put simply metatranscriptomics, a form of metagenomics, is able to attain data on gene expression, not just sequencing. This is a major step in the analysis of the human gut microbiome as with this advancement we move closer to finding out exactly which aspects of the micro biome lead to which effects on the human body.

I’m personally excited about advancements in this field, because it seems like the human gut micro biome is important to our health and well being. The more we know about it the more we’ll be able to treat our bodies healthily. Which would be great!

Eat Healthy! Your Food Can Cause Depression!

Think of it this way, the bacteria from your food intake remains in your gut for some time. This micro-gut biome is what produces an array of neurochemicals that the brain registers. At this point, the brain regulates some cognitive process with those neurochemicals. The processes include, memory, mood, and learning. Actually, a majority of the supply of serotonin in your body is produced and released by the bacteria in your body. Serotonin is a neurochemical that regulates mood. Thus, a deficiency in serotonin levels can cause depression.  Because of this, the gut is starting to be examined more closely to hopefully help find an easier, less invasive form for depression medication.  

Sander van der Wel, This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Genericlicense.

Current depression medication has harsh side effects on the body. As Professor Julio Licinio of Flinders University states, “Antidepressant drugs not only have side-effects which cause other health problems, but they also might not be the best solution for the mental health conditions they’re prescribed to treat,” it becomes evident that there is a void in the medical field. Professor Licinio and his team has high hopes that their gut biome research will serve as a way to fill that void and help millions of with their depression. Because there are 350 million people in the world that suffer from major depressive disorder, MDD, they believe that a simple test can improve the stand of living for the masses.  

Julio Licinio, This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.

Professor Licinio is also the head of the Mind and Brain Theme at the South Australian Health and Medical Research Institute, also known as SAHMRI. In conjunction with Ma-Li Wong–Head of Pharmacogenomics Research Program within the SAHMRI’s Mind and Brain Theme–, Geraint Rogers–Director of Microbiome Research within SAHMRI’s Infection and Immunity Theme–, and Steve Wesselingh–SAHMRI’s Executive Director, and the Infection and Immunity Theme Leader–, Julio Licinio are facing tribulations to inform the international community of the correlations between Obesity and Depression because, as Professor Wong states it, “we are in the midst of an obesity and depression epidemic.”

Have No Fear, Gut Microbes Are Here!

Ever dream about being a real life Captain America? Well, with the help of microbes, we are one step closer to achieving a “super soldier.” Microbes might not make a soldier muscular, but they can help with soldiers’ health and versatility. Scientist Jeff Tabor is working on engineering a probiotic organism that can help humans easily fight diseases, prevent obesity, and change their body’s ability to adapt to certain environments.

The gut bacteria affects many functions of the human body. The digestive system, immune system, and nervous system are all influenced by gut bacteria. Disrupting these microorganisms can cause indigestion, a weak immune system, depression, insomnia, and affect other cognitive abilities. Tabor’s goal is simply to create a microbe that can be consumed to prevent these problems.

Gut Microbe

Gut Microbe

Initially, Tabor wanted to use these microbes to target obesity because scientists have abundant knowledge of obesity at the molecular level. He recently succeeded in genetically modifying E.Coli to detect chemicals in the body that carry disease in mice guts. He hopes to use this modified E.Coli to sense chemicals in the gut that are connected to obesity and then use other molecules to prevent this obesity. The creation of a microbe that can control weight can be extremely helpful for the U.S. armed forces. For example, soldiers going from sea level to the top of a mountain way above sea level experience changes in temperature and pressure. Using this engineered gut microbe, the soldiers can put on weight to help them keep warm on top of the mountain and then lose weight to keep cool at sea level.

Another military benefit that these microbes can provide is to help soldiers operate effectively on little to no sleep or to help soldiers adapt to changes in their circadian rhythms, either from time change or going below sea level in a submarine. Scientists are interested in experimenting with the gut microbe to be able to achieve these goals in the future.

Some people might be afraid of the possible affects that these genetically modified bacteria might have on the human body. However, Tabor’s goal is for the bacteria to stay in the gut for about six hours to do its job and then self-destruct or die naturally to prevent the bacteria for staying in the body too long. There are other concerning issues about creating a microbe that can help prevent obesity. The creation would take away any incentive for humans to eat healthy and focus on their diets because they could just use the microbe to prevent gaining weight. Any new scientific experiment comes with its pros and cons, but using gut microbes for human health, especially for the military, can be a big step in the right direction.

Source Article

Depression Infection?

Melancholy_2

 

Major Depression Disorder (MDD), most commonly known as “Depression”, is typically thought of as a genetic or neurological disease. However, Dr. Tuhran Canli, Associate Professor of Psychology and Radiology at Stony Brook University, suggests that MDD be recategorized as a result of a parasitic, bacterial, or viral infection. Canli’s paper, Biology of Mood & Anxiety Disorders, argues how possible pathways from these infections could cause MDD.

The causes of MDD are still unclear, therefore the research is delving more into the causes over the treatments. Dr. Canli suggests that by redefining MDD as an infectious disease, it will push future researchers to focus their attention on parasites, bacteria, or viruses.

Canli’s three major arguments for this change of MDD’s etiology are as follows:

1. MDD patients have a loss of energy, typically found in an illness. Also, the “inflammatory biomarkers in MDD suggest an illness-related origin”.

2. Parasitic, bacterial, and viral infections alter emotional behavior in humans.

3. The body is an ecosystem, made for microorganisms and genetics. These infections alter that ecosystem.

The redefinition of the causes of MDD could have significant help in finding the cause and eventual better treatment of the disease. Has depression been an infection all along?

 

Original article: http://www.sciencedaily.com/releases/2014/11/141114124307.htm

Picture: http://commons.wikimedia.org/wiki/File:Melancholy_2.PNG

Antidepressants Change Brain Connectivity After One Dose

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Lloyd Morgan- “Despair”

The prescribing of anti-depressants is a controversial topic in that most scientists are unaware how these medications work. Previously, SSRIs (serotonin reuptake inhibitors) were thought to have taken effect after a few weeks. Recent studies show, rather, that these medications take effect in a matter of hours.

SSRIs are very widely prescribed and frequently studied as antidepressants. They work by fundamentally changing brain connectivity and the way in which the brain undergoes simple processes. New studies are showing that this rewiring of the brain occurs after only one dose of this medication, producing dramatic changes.

The Institute for Human Cognitive and Brain Sciences conducted this study by conducting extensive brain scans, allowing participants to let their minds wander so that the lab technicians could accurately measure the oxygenation of the blood flow in the brain as well as the number of connections between voxels in the brain.

This lab yielded interesting results. Scientists discovered that one single dose of SSRI reduced the level of intrinsic connectivity in most parts of the brain, but increased connectivity within the cerebellum and the thalamus.

This study opens up a lot of opportunities for deeper investigation into antidepressants. It can help researchers to understand why some people do not respond well to this form of treatment, and how to better individualize treatments for depression patients. Depression is a serious and life-altering illness that effects every sector of a person’s life. With added research and understanding of treatment methods, there can be hope for the many that struggle with this mental illness everyday.

Article Source: http://www.sciencedaily.com/releases/2014/09/140918121436.htm

Hypocretin: A New Avenue for Antidepressants

Depression is a major psychiatric disorder in the United States, affecting about six percent of the population. However, antidepressants in common use such as selective serotonin reuptake inhibitors (SSRIs) and other drugs have only flimsy evidence to support their efficacy. Recent studies suggest that positive results with these medications may be the result of the placebo effect rather than an effective treatment. Critics of current remedies for depression point out that they aren’t linked to observed deficiencies in certain hormones affect mood.

Scientists at the University of California Los Angeles Semel Institute recently discovered a new chemical, a peptide called hypocretin, directly linked to happiness and alertness. In their study, the scientists monitored patients undergoing treatment for severe epilepsy. “Piggy-backing” on the implanted electrodes from the patients’ treatment, the team monitored levels of hypocretin and MCH (or melanin concentrating hormone) throughout the day at 15 minute intervals. Notes of the patients’ activities were made simultaneously. Patients answered a questionnaire asking about their mood every hour they were awake. In analyzing their data, the scientists discovered that hypocretin was highest when patients experienced “positive emotions, anger, social interactions, and awakening.” In contrast, the MCH was highest during sleep lowest when hypocretin was high.

According to Professor Segel of the Semel Institute, who led the team that made this discovery, “The findings suggest that abnormalities in the pattern of activation of these systems may contribute to a number of psychiatric disorders.” Chemicals that counteract hypocretin are already being developed as sleeping pills, and hypocretin could provide the foundation for a new kind of antidepressant.

Oh, hey there Stress -.- Here to cause some more damage?

Taken on Yasmin Kibria's laptop

It’s everywhere. Whether it be school related, family or friends related–it’s always present. It’s an integral part of our lives. We’ve always known that stress has negative effects on our lives, but according to an article written by Alice Park, who has done a fellowship at Harvard University, stress shrinks the brain and lowers our ability to cope with adversity. Yay, even more negative effects of stress!

Researchers have found that even everyday stress can be leading to changes in the brain that make us more susceptible to social and psychological disorders such as depression and addiction.

Professor Rajita Sinha of Yale University School of Medicine and director of the Yale Stress Center has found that stress can cause shrinkage in parts of the brain responsible for emotions and metabolism, even in healthy individuals. Her research has found that it it’s not indiviual traumatic events that have the most impact, but the cumulative effect of a lifetime’s worth of stress that might cause the most dramatic changes in brain volume.

After imaging the brains of one hundred healthy participants who have had stressful events in their lives showed smaller grey matter in the prefrontal cortex.  This region is responsible for self-control, emotions and physiological functions.

The prefrontal cortex is known as the “CEO of the brain.” This region is responsible for cognitive analysis and abstract though, and the moderation of acceptable behavior in social interactions.Injury to this region can affect the ability to process information and solve problems, the abilities to concentrate, remember and learn.  Damage can also lead to personality changes that lead to impulsive and socially inappropriate behavior, depression and violence.

By further analyzation, Sinha was able to distinguish how different types of stress, such as divorce, death of a loved one, or loss of a job, affect different regions of the brain.  Recent events, such as finding out of a medical diagnosis, affect emotional awareness.  When this part shrinks, we strat to lose connection with our emotions, and as a result, act inappropriately in interactions with other people.

More serious events, like life traumas, such as living with cancer, affects our mood centers which skews our ability to regulate pleasure and reward.  A shrinkage in this area is also linked to depression and other mood disorders.

Lastly, chronic stress, stress we deal with every day doesn’t affect brain volume on its own.  This type of stress erodes parts of the brain slowly and gradually.

It’s important to keep in mind that stress can build up and lead to negative results and effects on the brain.

How can we alleviate stress? There are hundreds of things you can do: yoga, exercise, making lists, etc.  It’s also important to maintain strong social and emotional relationships because others can help as well.

 

Vitamin D is linked to depression, so start sunbathing!

Haven’t been in the sun too much this winter season and feeling depressed? Well, it may be due to the fact that low levels of vitamin D are now linked to depression. According to a recent article, low vitamin D levels are already linked to cardiovascular diseases and various neurological problems. However, a new study links the connection between low vitamin D levels and depression. At the UT Southwestern Medical Center, researchers examined 12,600 subjects from 2006 to 2012. Results showed that subjects with higher vitamin D levels, who had a previous history of depression, had a larger decreased risk of depression at the time. Participants with low levels of vitamin D were shown to have signs of depression. Although the study the relationship of vitamin D and depression, the study did not show if increasing vitamin D in your diet actually reduced those depressive-like symptoms. Also, scientists have not confirmed whether or not low vitamin D causes depression like symptoms or if depression is causing low vitamin D levels. One could say low vitamin D levels are linked to depression however, adding vitamin D to your diet would not necessarily cure depression-like symptoms.

Many concepts around the idea of vitamin D being linked to depression are still unknown, but I think it is still a very important topic to discuss and important further research the subject.  The psychiatrists the UT Southwestern Medical Center have reported that major depressive disorder affects one in ten adults in the United States. One-tenth of our adult population has depression. When you put it into perspective, that is one person in a room of ten people. If that is the case,  then for me this is a field where the link between vitamin D and depression needs to be further researched. For now, it won’t hurt some sunshine to get your daily dosage of vitamin D.

 

Cheer up, its not depression, its just hypothydroidism

Have you ever felt depressed and you don’t want to take pills to make you feel better? If the answer is yes then you might be in luck. A recent article in The New York Times reports on scientists finding a correlation between some cases of depression and levels of thyroid hormones in the blood. The specific hormones are Thyroxine and Triiodothyronine known as T4 and T3 respectively which regulate a wide variety of things such as body temperature and cognitive functioning. There are two cases which can have an irregular effect on the body. The first is hyperthyroidism which is having too much of the thyroid hormone which can cause a faster metabolism, sweating, weight loss and anxiety. The other case is hypothyroidism which is having too little of the thyroid hormone which can cause physical fatigue, weight gain, and depression which is what Dr. Russell Joffe, a psychiatrist, has been looking into. He says that “treating [hypothyroidism], which affects about 2 percent of Americans, could alleviate some patients’ psychiatric symptoms and might even prevent future cognitive decline.” Patients can be given synthetic thyroid hormones such as levothyroxine if their thyroid stimulation hormone, or TSH, is too high.

This subject is still controversial because it is hard for some doctors to tell what an abnormal level of TSH is since the normal levels can range from 0.4 to 5. This is only a problem if one doctor sees a patient with a 5 and thinks nothing of but if the normal level for the patient is 0.5 then the patient has 10 times as much TSH than they should have. Other cases can be difficult since it is sometimes hard to tell if it is a case of depression or if it is just stress and anxiety instead of mild depression. The research is still being done on trying to get a better sense of how the thyroid hormones and mood link.

You aren’t always that good

Credit: newwavegurly flickr

Have you ever been to an athletic event where everyone gets a trophy no matter how well they do?  This is done so kids will not feel like they are not as good as their peers.  It teaches kids that it doesn’t matter if you come in first or last as long as you try your hardest you will be rewarded.  This may not sound like a big deal but a recent study  has found that this undeserved positive reinforcement can actually lead to depression.

Young-Hoon Kim and Chi-Yue Chiu, two scientists from Singapore, conducted a research project that involved over 3,000 students from ages 12 to 22.  The students were placed into four groups.  In the first two experiments, two of the groups were given age appropriate academic tests and were asked to rate how well they thought they did compared to other participants their age.  The participants were then given a questionnaire that is used to measure depression .

In the third and fourth experiments, the two remaining groups were also given age appropriate academic tests but this time the students were not asked to rate their performance.  Instead, the students were given false information about their scores.  The students who had very high results were given negative feedback and the students who did badly were given positive feedback.  A control group was formed and when they received their scores they did not get any feedback.  After receiving their scores, these students were given the same questionnaire as the first two groups of students.

The results show that students who rated their performance higher then it actually was were much more likely to feel depressed then those students who more accurately rated their performance.  This proves that falsely telling yourself that you are good at something does not benefit you. By telling yourself you are good at something that your not good at, you are actually making it harder for yourself to succeed.

We are taught from a young age that we will be rewarded for putting in a good effort and trying our hardest.  This is not always the case and can lead to us believing that we do not have to try hard to get what we want and our performance level may decline which could cause depression and low self-esteem.  

Remember to be honest with yourself and those around you because even though you may think you are doing a good thing by telling others that they are good you could be setting them down a road to depression.  Honestly truly is the best policy.

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