AP Biology class blog for discussing current research in Biology


Dr. Apryl Pooley: The Incredible Neuroscientist, Activist, and Survivor Illuminating Sex Differences in PTSD Symptoms

“Trauma#neuroscientist,#author, artist, social justice activist, mental health advocate, unionizer, survivor/recover-er/contender of rape/addiction/#PTSD” This is the Twitter bio of Dr. Apryl Pooley, a neuroscientist who is studying sex differences in traumatic stress response using sperm producing and egg producing Sprauge-Dawley rats. Through her work, she came to the discovery that “trauma has divergent sex-specific effects at the behavioral, physiological, and cellular levels,” an idea that hasn’t been explored in modern neurobiology. 

A visual of the release of ACTH in response to a stressor

Dr. Pooley and her research team utilized two known identifiers of PTSD-like response in rats to monitor these differences between the males and females. One was the acoustic startle response (ASR), an involuntary contraction in the facial and skeletal muscles “to a sudden and intense startling stimulus,” and the other was the dexamethasone suppression test (DST), a test used to examine adrenal gland function after the administration of dexamethasone, a steroid that “provides negative feedback to the pituitary gland to suppress the secretion of adrenocorticotropic hormone (ACTH),” which is released in copious amounts in the presence of a biological stressor. In PTSD patients, enhanced ACTH suppression is consistently found after this test is performed, since the patient responds to the negative feedback loop which quells the excessive release of ACTH. While the male rats demonstrated a high startle response and this expected negative feedback control in the pituitary and adrenal glands, the female rats showed symptoms more common to depression in response to the stressor. This contrast lead to Pooley’s conclusion that the “trauma response of male and female rats is fundamentally different,” and that it is important to understand these differences to pave “the way for improved diagnostics and therapeutics that effectively treat both men and women.”

Her interest in trauma and PTSD, especially her “goal of determining how a traumatic event affects people differently,” stems from her personal experiences and struggles. While she was researching Parkinson’s disease in her doctoral training at MSU, she came across studies of PTSD symptoms and realized that is what she had been coping with her entire life after being raped as a teenager. She “didn’t know that rape could cause PTSD,” and became dedicated to helping others learn about the devestating effects and causes of traumatic stress response. She also struggled with an alcohol addiction to cope with her trauma and eventually sought help from counselors and psychiatrists. During her journey of recovery from alcoholism, she wrote a book about her experiences titled Shadow Brain: A Neuroscientist’s Journey through PTSD and Womanhood and changed her Ph.D. research to looking at PTSD, with a concentration on how symptoms present in women. 

Dr. Pooley is an inspiring scientist, activist, and survivor that is making history with ground breaking research in behavioral science. She is “excited” to continue finding “biological evidence for why men with PTSD tend to show signs of aggression and anger and women with PTSD tend to show signs of anxiety and depression” and shedding light on how behavioral health disorders and trauma affect women, a topic underrepresented in current scientific research. She especially hopes that her work leads to the development of increasingly effective treatment resources for sexual assault survivors, women, and LGTBQ+ people who have experienced trauma or struggle with PTSD. How do you think we can amplify the voices of female scientists studying behavioral health and trauma like Dr. Pooley? How do you think her work is changing the portrayal of behavioral and mental health in the scientific community? 

Gut Microbiome is Responsible for PTSD?

Recently, there have been many studies linking gut microbiome to PTSD. But how exactly are they connected?

Humans have an infinite number of organisms creating a unique composition of bacteria in the gut. It has been suspected before that any number of combinations of these gut microbiome can affect our health in different ways. One way is that they can cause neuropsychiatric disorders like PTSD or even just weaken mental toughness. Either way, the topic of gut microbiomes is definitely worth researching.

A recent study conducted by 22 scientists at Stellenbosch University in South Africa showed that compared to healthy, unaffected people, those with PTSD had noticeably lower levels of three gut bacteria: Actinobacteria, Lentisphaerae, and Verrucomicrobia. However, it was also noted from that study that the loss of these three gut bacteria may have occurred in earlier stages of life rather than the later stages when people generally develop PTSD.

According to a study conducted by researches of Oregon State University, when someone suffers from stress, their gut microbiomes become disordered and start to act oddly. Therefore, the lower levels of the three gut microbiomes could indicate that the levels of those microbiomes are throwing off the balance that is needed to maintain a stress and anxiety free mind which can prevent PTSD.

There is one catch about this result: that correlation does not confirm anything. Scientists conducting studies could only identify a correlation with gut microbiome and PTSD, but could not determine a cause.

Many are hopeful that these results will lead to discovery of future treatments because the microbiome can easily be changed with prebiotics, probiotics, synbiotics, or just dietary changes.

Although we do not know if these three gut microbiomes cause PTSD or come with PTSD, we do know that we are now one step closer to finding a cure or at least a better treatment for PTSD.

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Predetermined diagnosis of PTSD and Depression can lead to prevention of psychological disorders

According to Science Dailyquestions that tests the psychological attributes that deal with coping ability, adaptability, and optimism. The questions are used to identify high-risk individuals and provide them with psychological and social resources to help them cope with the troubles dealing with deployment.

Researchers created an individual score that composites the soldier’s risk using baseline psychological attributes and demographic information such as martial status, gender, race, education and military occupation group.They found out of those whose score classified them as being at highest risk for psychological health disorders , which is at the top 5% of the score, 31% screened positive for depression, while 27% screened positive for PTSD after return from deployment.

 Professor Yu-Chu Shen, lead author of the study said: “We found that soldiers who had the worst pre-military psychological health attribute scores — those in the bottom 5% of scores — carried much higher odds of screening positive for depression and PTSD after returning home than the top 95%. Soldiers who score worst before deployment might be more susceptible to developing debilitating mental health disorders when they are later exposed to combat environments.”

The results suggest that psychological screening before deployment can be helpful in identifying the individuals who carry significant risk for psychological health disorders. Being aware of this risk could enable interventions to improve soldiers’ psychological health prior to exposing them to combat.


Predict PTSD?


Brain Scan by Reigh LeBlanc. Found on Flickr

Researchers at the Tohoku University have recently discovered that weak connections in specific parts of the brain are connected to the incidence of post-traumatic stress disorder. The study will be able to help predict if a person is susceptible to PTSD just by looking at scans of a brain.

The scientists compared information from men and women who experienced the Japanese earthquake of 2011. Before the earthquake, the researchers had already scanned the students’ brains. This way, the researchers could compare the brain’s white matter before and after the traumatic event. The white matter is responsible for the connections and communication between various regions of the brain.

According to the researchers, “participants who had weak connections in the front, right section of the brain before the disaster were more likely to have high levels of anxiety after the earthquake hit.”

The new discovery will be able to help predict PTSD. Dr. Atsushi Sekiguchi, a researcher at the university, believes that the study will help the military predict “PTSD vulnerabilities” before the deployment of troops.

More research is needed before scans of the brain can predict PTSD. According to Sekiguchi, scientists now have to figure out the “threshold” that would mark a person as susceptible to PTSD. The study’s results can help prevent PTSD in the future by identifying people with PTSD vulnerabilities.

What do you think about this discovery?

The Brain after Combat

The fact that many soldiers suffer from brain damage after combat is no new discovery. One difficult soldiers experience  is  with tasks requiring memory or attention.This is a potentially devastating side effect of serving your country. Because of the weight of this debilitating deficit, scientists continue to research the effect military combat can have on the brain. A study that began by testing the way the brains of “healthy Dutch soldiers” respond to stress in normal life led to important discoveries about the way the brain responds to stress after combat.

This is an American soldier in combat who is subject to the “adverse stress reactions explored in this article.

The areas of the brain that suffer notable damage are the mid-brain and the prefrontal cortex. As before mentioned, these parts of the brain are associated with memory and attention. Soldiers were tested on their memory and attention skills before combat and then again after returning from combat. There were significant differences in the two studies, with alarmingly lower scores in the second round of testing. There is lower activity in the mid-brain and the prefrontal cortex and also a weaker connection between the mid-brain and prefrontal cortex. However, scientists determined that in most cases the brain can heal and return to normal functioning levels after a year and a half.

This was an exciting discovery because it gives hope to any soldiers suffering from the “adverse effects of stress”. This is also an important discovery because it leads to the suggestion of longer periods of time between combat tours. It is uncertain whether or not the brain can heal after “Multiple stressful deployments in quick succession“.

I think it’s important to fully consider giving soldiers more time to recover between tours. This would hopefully prevent long-term damage to vital brain functions.

This issue and discovery are even more relevant to Americans because of the links in brain trauma due to combat and brain trauma due to football. The leaders of the NFL and of the US Army are working together to “improve awareness of traumatic brain injury and further research into its causes, prevention and treatment.” This collaborative effort is focused on prevention of traumatic brain injury by promoting early detection of concussions. If a soldier or player is aware of his or her concussions as they happen they are more likely to take time off to heal before re entering the battle field or playing field.


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Stress is Good for you?

Does this look familiar?

High school is stressful. Students are forced to balance heavy loads of school work on top of family obligations and time-consuming extracurricular activities. We all know a little bit of stress is healthy, providing just enough motivation to give you a kick in the butt, but not enough to make you want to pull your hair out. However, when finals time rolls around and you’re ready to cry because you’re so overburdened, then stress becomes a problem. When you’re stressed, glucocorticoids, or stress hormones increase the level of cortisol in your body, prepping it to take on the physical demands of stress. (In terms of evolution, being under stress is being chased by a lion that thinks you’re dinner, not taking the SAT tomorrow). Science has always told us that stress is bad for us; high levels of cortisol are linked to depression and high levels of cortisol over prolonged periods of time actually impair our ability to cope with stress. Just reading about this is stressful, right? But what if I told you that stress might actually be good for you, at least in one respect. A new study conducted by Ranjish Rao and published in Biological Psychiatry shows that high glucocorticoid levels could potentially help reduce the development of PTSD, or Post-Traumatic Stress Disorder.


No, I’m not Crazy. Stress Really Can Be Good for You

PTSD is caused when a person witnesses a traumatic, potentially life-threatening event. For example, combat soldiers and children who were sexually abused often times suffer from PTSD. Recent studies show the “trauma” in PTSD is the impact of stress on the brain structure of the victim, according to Dr. John Krystal, editor of Biological Psychiatry. The study conducted by Rao was inspired by an odd occurrence: clinical reports showed people with low cortisol levels were more likely to develop PTSD, and that cortisol treatment actually reduces the symptoms of PTSD. The study used a model of a rat to study its stress levels in relation to corticoids. Professor Chattarji from the National Center of Biological Sciences in Bangalore, India explains the outcome of the experiment: “ We were able to…. identify a possible cellular mechanism in the amygdala, the emotional hub of the brain [responsible for this odd occurrence.]” It turns out the number of synapses in the amygdala is a fairly accurate predictor of whether or not a person will have high or low anxiety levels. The corticoids given to the rats reset the number of synapses in their amygdalas, and brought down their stress level.

So What Does this Mean for Me?

If you’re a high-stressed, health conscious person like me, after reading this you might feel slightly better about your high stress levels, but don’t celebrate just yet. Even though we all have the potential to develop PTSD, not everyone does, so this study is relevant to only a portion of the population. Even if it were relevant to everyone, the stress hormones in the study were given to the rats under controlled circumstances, and if this were to become an actual therapeutic treatment for PTSD, the patient would most likely ingest corticoids under the close watch of their psychiatrist. In my opinion, the damage caused by high glucocorticoid levels far outweigh the benefits. So, take a deep breath and relax. Maybe go for a run or talk with a friend. Your stress will eventually go away.




Bad day? Just sleep it off

Credit: Cami Marlowe

Have you ever had a bad day and woken up the next morning in a good mood?  This is because a recent study has shown that while dreaming at night during periods of REM sleep, the brain is in an environment where the is a low amount of stress chemicals.  The brain being in this state helps to take the strong emotion out of sad or hurtful memories. Matthew Walker, an associate professor of psychology and neuroscience at the University of California, Berkeley has said that “we feel better about the [memories] because we feel that we can cope.”

Walker wanted to figure out if he could use this logic to help people suffering from PTSD.  These peole are unable to recover from their painful experiences even after years of being away from the trigger.  Researchers have found that the overnight therapy does not work well for people with PTSD because there may be many triggers that occur during the day such as a car backfiring that bring back the emotion that was unable to be fully wiped away with sleep. It has also been found that people with PTSD and other mood disorders are not able to get a full night of uninterrupted sleep.

In order to try and help those with PTSD, Walker wanted to learn more about the curing power of dreams so he conducted a study in which 35 healthy adults were divided into two groups.  Both of the groups were shown a series of 150 pictures that were meant to evoke emotion.  While they were looking at the pictures there brain was being looked at with an MRI.  One of the groups were shown the series of pictures in the morning and then again at night without sleeping for anytime between the two viewings. The other group was shown the series of pictures at night and then again in the morning after a

full nights sleep. The results of the MRI were very interesting. The MRI showed that the people who were allowed to sleep between viewing the pictures had a much less significant emotional reaction to them the second time. The part of the brain that processes emotions was much less active which allowed the rational part of the brain to control the emotions.  While the participants slept researchers noticed that there were less stress chemicals in the brain then while they were awake.  This could mean that the emotion from seeing the images was being diminished.

So what does this mean for those suffering from PTSD? Walker found out that a type of blood pressure medicine was able to suppress the stress chemicals found in the brain. When less stress chemicals were present, the PTSD patients were able to have more REM sleep and therefore, reduce the night mares and have a better quality sleep which allowed them to begin to recover.

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