BioQuakes

AP Biology class blog for discussing current research in Biology

Author: mitochondriya

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? 

“Covid Winter” is Coming: The Power of Humidity in our Return to Normal

As “Covid Winter” approaches, especially in states with seasonal changes such as New York, it calls into question what this will mean for the virus in the coming months. When thinking about when the pandemic will end, temperature, humidity, and seasonal shifts are large factors which work against stopping the spread of the virus. Externally, as the air outside becomes colder, it is able to hold less water vapor, which decreases humidity. HVAC (heating, ventilation, and air conditioning) units inside office buildings work by taking in outside air and heating it to channel through the indoor space, which similarly dries the air out. 

Why is humidity important in preventing the spread of the virus on a biological level? In an aerosol study conducted at Virginia Tech, the researches demonstrated that as humidity levels decrease, the particles of moisture released from actions such as talking, coughing, sneezing become smaller. This becomes a problem because the dry air causes the water in the molecules to evaporate faster, therefore becoming even smaller and staying in the surrounding air for a longer period of time. Any droplets can then travel around the closed, indoor space further. Their minuscule size allows them to be inhaled and move deeper into the lungs, where, as we learned in the video we watched in class, a spike on the virus will insert into a receptor molecule on a healthy cell membrane, allowing it to infect the healthy lung cell, leading to a susceptible person contracting COVID-19 and being able the virus further.

Other coronaviruses, like the common cold, influenza, and rhinoviruses, have exhibited similar spreading patterns dictated by the seasons, demonstrated by flu season occurring in the winter, calming down in summer, and coming back again in fall. Scientists believe COVID-19 could do the same, and are currently conducting research and gathering data to see the correlation between the virus and humidity levels. Stephanie Taylor, a physician and fellow at Har-

An example of how the virus remains in the air after released through talking, singing, etc

vard Medical School, is part of a joint study with the Massachusetts Institute of Technology that “found that the most powerful correlation between national numbers of daily new coronavirus cases and daily Covid-19 deaths was indoor relative humidity.” In reflecting upon their findings, she says that humidity “is so powerful, it’s crazy.” 

The only way to know exactly how the coming winter months will affect the spread of the virus is through time and observation, but it is interesting to look at the biological processes and movement of particles in relation to humidity to understand how the virus may have an increased spread as it becomes colder. I also feel this background helps us be able to make intelligent, informed decisions about the risk of social gatherings as it becomes harder to stay outdoors and the weather changes. What do you think is lying ahead in “Covid Winter?” Do you think we will inevitably have to wait until the humidity changes in spring to declare an official end to the pandemic? 

 

A Super Self-Assembling Vaccine Booster to the Rescue!

Vaccines: a topic on the forefront of the minds of scientists, researchers, and the general public. With the novel coronavirus and fiery online debates led by coined “anti-vaxers” about the effectiveness and dangers of vaccination, biologists are racing to discover more methods to improve these life-saving injections. An essential component of many vaccines, including ones used to prevent cervical cancer, influenza, and hepatitis is the adjuvant: a “booster” ingredient that helps the vaccine create a longer-lasting, stronger immune response in the patient. Recently, a team of scientists in Japan discovered a new adjuvant—a molecule called cholicamade—that was equally as effective in treating influenza in mice as its predecessor, Alum. The emergence of this new ingredient is exciting, but the real novelty lies in the process these biologists used in discovering chloicamade: looking at molecules that could self-assemble.

What is the self-assembly of a molecule, or multiple molecules? Multiple molecules are said to self-assemble if they are able to organize into a defined pattern without the intervention of an external source, such as heat. These molecules will form ionic or hydrogen bonds with each other, similar to the joining of water molecules, since they don’t share electrons equally, as we learned in AP Biology. Identifying molecular structures that self-assemble is a common practice in materials science, but not often used in researching adjuvants. This team of biologists and chemists hypothesized that utilizing molecules that form in this fashion for disease treatments may be effective because pathogens in viruses also form through self-assembly. They wondered if a similar method in structural formation between a treatment and its virus would trigger a similar immune response.  

And it did! Cholicamide self-assembles through ionic bonds to create a structure which looks almost identical to a virus, triggering the same immune system cells to react. The structure of the molecule

An image of the influenza virus, which the treatment would attempt to replicate.

lends itself to the formation of ionic bonds because of its inherent polarity and electronegative elements. The molecule can be injected directly into vacuoles that will connect it with the specialized receptors which will trigger the appropriate immune response. A vacuole’s ability to store water and other nutrients (as we learned in AP Biology) as well as transport these nutrients throughout an animal cell is vital in ensuring the treatment binds to the correct receptors. Uesugi, a leading scientist in the study, hopes “the new approach paves the way for discovering and designing self-assembling small molecule adjuvants against pathogens, including emerging viruses.” What do you think about this new method in discovering vaccine treatments? How do you see the future of vaccines changing as more adjuvants are researched? I believe there is nothing more exciting than not only confirming the effectiveness of a new treatment, but also conducting the research with a new approach or perspective.

 

 

 

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