Author Archives: Kayla Palmer

Heart Health: Slowing the Progression of Heart Failure
Amal Altaf
Junior
Biological sciences (BS) and global health (BA)
Barrett at Arizona State University

My Research Project

Cardiac fibroblasts are cells in the heart that are involved in producing proteins such as collagen. An accumulation of these proteins leads to a medical diagnosis termed fibrosis, which plays a major role in the progression of heart failure. Proteins such as angiotensin II are known to activate fibroblasts and promote fibrosis. Reactive oxygen species (ROS) are unstable molecules in the cell that have been suspected to play a role in angiotensin-II-induced inflammation and, consequently, fibrosis. An imbalance of ROS in the cells is called oxidative stress. While no treatment is known to reverse fibrosis, a class of drugs known as angiotensin converting enzyme inhibitors (ACEI) are able to slow its progression, even after ACEI treatment has been stopped. However, it is unknown how ACEI treatment is able to protect against fibrosis.

In this experiment, I was tasked with investigating whether the protection against fibrosis was a consequence of a more favorable oxidative stress profile in response to angiotensin II treatment. Using heart tissue from the left ventricle of rats my lab was able to test our hypotheses. The rats were divided into three treatment groups, each treated for a total of six weeks, The treatment proposed on the rat models is depicted by the table below.

Because ACEI has been previously shown to protect against fibrosis, we hypothesized that hearts from hypertensive rats previously treated with ACEI would show decreased protein expression of pro- and anti-oxidant enzymes in response to angiotensin II, which corresponds to Group 3 in the table above. Understanding whether oxidative stress is altered due to prior ACEI treatment will allow for a better understanding of the mechanisms through which the heart can become more resistant to fibrosis. This may contribute to a better understanding of cardiac fibrosis and the development of novel treatments that may slow or prevent heart failure.

Realities of Research

Loading of Western Blot gel.

It surprised me, but I quickly learned that research involved a great deal of trial and error. I learned that while every step in the research plan is well thought out, there is still a lot of uncertainty. However, that was not a bad thing, because that uncertainty is exactly what we are targeting through our research. We sought to understand things we did not already know. My experience this summer forced me to learn new techniques, such as those of western blotting, imaging via film, and technology and analysis. I was also been fortunate enough to shadow others in the lab and gain better understanding of several other procedures such as surgeries, cell culture and immunohistochemistry.

More often than not, the results I received were different from what I expected, which led to several discussions with my research host about possible explanations and potential next steps, very often being revised. It almost reminded me of the game “Chutes and Ladders.” We would make progress in the direction we expected, then come across unexpected results which sometimes brought us back to square one or took us in a new direction. I’m not entirely sure how many times we had to start over, but we certainly had to go back and change our plan several times. We actually just revised our research question a few weeks prior to wrapping up the summer research!

Life as a Scientist

The daily life of a scientist is much more than mixing chemicals and making graphs. My life as a scientist this summer provided me with insight into the reality of working in a research lab. Beyond the trial and error, the uncertainty and the constant learning that all made each day in this field so intriguing, there was also a great amount of collaboration involved. Working as part of a team was one of my favorite parts of being a scientist. I worked towards a common goal with my lab team, but also worked with people outside of my lab, even those whose research had a different focus. My least favorite part of working in the lab was how writing-intensive it was.

When picturing a scientist, a person in a lab coat working at a lab bench usually comes to mind. In reality, the life of a scientist involves a considerable amount of writing in order to obtain grants to fund the research and to communicate the research. While this hasn’t been completely applicable to my case (since I’m not writing grants—yet!), I would still consider it to be the “worst” part about the day-to-day life of a scientist. All in all, my time in the lab this summer allowed me to gain an invaluable understanding not only of the research project I worked on, but also the realities of research and the life of a scientist.

Amal Altaf is a junior double majoring in biological sciences and global health at Barrett, The Honors College at Arizona State University in Tempe, Ariz. She is a 2019 Undergraduate Summer Research Fellow (UGSRF) working in Dr. Taben Hale’s lab at the University of Arizona College of Medicine in Phoenix. Amal’s fellowship is funded by the American Physiological Society. Upon graduating, Amal hopes to pursue medical school to eventually practice as a physician

Summer Study: A Journey from Heart to Kidney
Yuliia Kashyrina
Sophomore
Pre-allied health major
Howard Community College, (Columbia, MD), class of 2020

My Research Project

When asked about the most vital organ in the body, most people would point out the heart without hesitation. It is indeed an essential pump that helps deliver oxygen and other nutrients from food to the body’s cells. The heart also helps fight infection and creates blood clots after injury. The principal function of the heart is maintaining solute circulation. When it comes to removing these solutes, the kidney kicks in. Without the kidney, the blood would accumulate metabolic waste made by the body as a result of your activities, drastically increasing the pressure in your blood vessels due to a large amount of solutes being added.

On a large scale, my project investigated a possible mechanism by which the body can function to lower your blood pressure. On a smaller scale, I investigated the effect that a hormone released by your heart can have on certain types of kidney cells.

Realities of Research

Working in a research lab was fun. Fresh out of school, I rejoiced in this great feeling of assuming responsibility (finally) for every part of the project from the experimental design and hypothesis, to implementation, statistical analysis and drawing conclusions. I learned how to passage cells into various flasks, petri dishes and transwell inserts, how and when to feed them andhow to freeze them. I also learned different techniques of fluorescent imaging which uses fluorescent dyes to label molecules of interest, protein concentration measuring techniques, measuring current/resistance of cells in transwells and measuring cellular oxygen consumption rate, which was essentially how certain cells “breathe.”

Even with a very insightful mentorship from senior personnel in the lab, it took some time to tailor every protocol so that my experiments would produce clear results. In some cases, an experiment was great in theory but challenging to reproduce. For example, when we attempted to track changes in the mitochondrial calcium in response to acute application of the drug using a fluorescent dye, the drug delivery technique would greatly affect the results. It is no doubt that this particular experiment required a little bit more work, but within the 10-week time frame of my fellowship that experiment did not make the priority list.

Life as a Scientist

The best—and probably the worst— part about doing research was sometimes having to come to the lab at 7 a.m. on a Sunday. At the same time, I was able to have proper time off work so I could start a new week fresh and well-rested. Sometimes, however, my curiosity led me back to the lab again and again. In the end, there were two main things that I got most out of this summer:

  1. I cannot expect immediate results in science; and
  2. no science would be possible without collaboration within and outside of lab.

I did a lot this summer, from reading articles so that I stayed on track with discoveries, watching others do procedures, attending meetings and journal clubs, making presentations—you name it! Working in basic research is definitely a lot more than making hypotheses and carrying out experiments.

Yuliia Kashyrina is a sophomore majoring in pre-allied health at Howard Community College in Columbia, Md. She completed the Undergraduate Summer Research Fellowship (UGSRF) through the American Physiological Society during summer 2019 and worked under Dr. Daria Ilatovskaya at the Medical University of South Carolina, Division of Nephrology, in Charleston, SC. The UGSRF program was funded by the American Physiological Society. Yuliia is planning to transfer into biology/biological sciences to a four-year university in the fall of 2020 and seek an advanced degree in physiology upon completion of her bachelor’s degree.

What Comes First: Phrenic Motor Neuron Loss or Neuromuscular Junction Dysfunction?
Ann Mary Wilfred
Fourth Year
Health sciences major with biomedical specialization
McMaster University

My Research Project

Drawing of the chest cavity with the diaphragm colored in red.

As we age, there are many changes that happen in our body. One of these changes is the loss of phrenic motor neurons (PhMNs), a specific type of neuron that controls the diaphragm, the main muscle we use for breathing.

In older adults, the consequence of this loss of neurons is the inability to clear the airways through high-force behaviors like coughing and sneezing. Not being able to clear the airways may lead to infection and sometimes, death. With aging, the connection between these PhMNs and the muscle fibers it innervates—called the neuromuscular junction (NMJ)—breaks down because the PhMNs withdraw their connection from these muscles in a process called pre-synaptic withdrawal. The problem is that we do not know which event happens first: PhMN loss or pre-synaptic withdrawal.

My project aimed to chronicle a timeline of these events using a specific type of imaging technique called confocal microscopy. Being able to identify the sequence of events may help us pinpoint areas of therapeutic intervention in order to prevent or delay PhMN loss and NMJ dysfunction.

Realities of Research

Although I have participated in previous research activities, this summer fellowship was my first experience in a wet lab. It was a very valuable opportunity because I learned a wide variety of wet lab techniques, such as immunohistochemistry staining and how to handle rodents. What surprised me most was how much trouble-shooting was required— there are so many things that can go wrong! My project was mainly focused on imaging PhMNs. The biggest learning highlight of this project was learning how to use a confocal microscope and quantitatively analyzing the images. Initially, I felt intimidated because the process seemed so complex, and this was a very advanced and expensive piece of equipment. However, after imaging and analyzing so many samples, I am proud to say that I feel comfortable using this type of technique. I was happy to see that the experiments worked and the results were what I expected:that pre-synaptic withdrawal precedes PhMN loss in the NMJ and that large PhMNs seem to be more vulnerable to this loss.

Life as a Scientist

Working in the lab was an amazing experience! There were moments where it was very hectic, days when I had to go home later than usual or even times when I felt very frustrated because the work was tedious and laborious. Despite all of this, the experience was very rewarding because of the friends I made in the lab, the valuable networking opportunities I was engaged in, the important connections I made and most of all, the unique satisfaction I experienced when the experiments worked properly. In the end, I had really good data that I can contribute to a paper or publication.

I am grateful to have had the opportunity to work in a very supportive and welcoming lab environment; my lab mates, research mentor and principal investigator were always so receptive to my questions and concerns and helped mold me into the scientist and researcher that I am today.

It feels amazing to know that my research is contributing in a meaningful way to the larger goal of improving age-related respiratory dysfunction in hopes of someday helping so many people.

Ann Mary Wilfred is a senior in the Bachelor of Health Sciences (biomedical sciences specialization) at McMaster University in Hamilton, Ontario, Canada. She is a 2019 Undergraduate Student Research Fellow (UGSRF) working under the mentorship of Dr. Gary C. Sieck at Mayo Clinic in Rochester, Minn. Ann’s fellowship is funded by the American Physiological Society. After graduation, Ann plans to pursue a career in medicine, specializing to become a pediatric neurosurgeon, while also continuing her involvement in neuroscience and physiology research.

Biomechanics to improve running performance
Gemma Malagón
2019, senior
Biomedical engineering
Tecnológico de Monterrey, Mexico

My Research Project

As a Fellow from the American Physiological Society (APS), Hearst Undergraduate Summer Research Fellowship, I was grateful to have had an opportunity to work under Dr. Arellano at the University of Houston at the Center for Neuromotor and Biomechanics Research.

My research this summer focused on the biomechanics of arm swing across different walking speeds and its effect on the metabolic cost. Our main objective was to better understand the passive and active contributions by examining the electromyographic (EMG) activity of the muscles involved in arm swing, with a special focus on understanding how changes in EMG amplitude in the upper limb varied across walking speed.

The data acquisition consisted of:

  1. Measurements of oxygen consumption and carbon dioxide production using indirect calorimetry, which is a process that measured the amount of heat that was released or absorbed during a chemical reaction;
  2. XYZ coordinates of joint positions, which has the objective to understand the kinematics of the body;
  3. Ground reaction forces; and
  4. Muscle activity of arm muscles of interest.

These measurements allowed us to compute and compare metabolic power, joint angles and mechanics and average muscle activity patterns when walking with and without arm swing.

Realities of Research

The research that I conducted was exciting and it was a wonderful experience working in the lab. In the beginning, I spent most of my time reading articles and doing research on my assigned project. I had an engineering background prior to my summer research, so one of the aims of my research project was to develop an efficient MATLAB code to process and analyze the EMG data collected on the studies.

I have learned to measure my progress due to the number of setbacks I had, which also helped me realize different paths which brought me closer to reaching my goal. I have learned more than I could ever hope and was fortunate to have had the opportunity to work—even for a little while—with some of the most talented and coolest people in the U.S.

Life as a Scientist

I made the decision to study biomedical engineering with a concentration in research driven by my desire to contribute to fundamental breakthroughs in medicine and become a better Mexican-researcher. This past summer, besides working on my own research, I’ve was involved in many lab projects, so I realized how amazing it is when you work with people who share the same passion as you. The truth is, having to work eight hours a day during the week, and some days even more, might be tiring! This was especially true when I would have to take the bus for two hours to get to the lab and two more hours to get back home. However, it was a unique experience that not everyone is willing to take advantage of. Participating in this program not only widened my research experience, but it has helped me on my path towards a master’s degree, which I plan to pursue after I graduate.

Reference:

Christopher J. Arellano, Rodger Kram. Journal of Experimental Biology 2014 217: 2456-2461; doi: 10.1242/jeb.100420

Gemma Malagón is a senior majoring in biomedical engineering at the University of Tecnológico de Monterrey in Mexico. She is a Hearst Undergraduate Summer Research Fellow working in Dr. Arellano’s lab at the University of Houston, Health and Human Performance Department. Gemma’s fellowship is funded by the American Physiological Society and Hearst Foundations. After graduation, Gemma plans to pursue a master’s degree in clinical and sports engineering.

Acknowledgements

I would like to express my deepest appreciation to Hearst Foundations and the American Physiological Society (APS) for my research fellowship, and to Dr. Christopher J. Arellano, which the completion of my internship would not have been possible without his support and mentorship.

Why are frogs able to survive in low oxygen conditions?
Bianca Okhaifor
2020, senior, biology major/chemistry minor
University of North Carolina at Greensboro

My Research Project

Credit: Drew R. Davis, Amphibians and Reptiles of South Dakota

Most living organisms rely heavily on oxygen (O2), a major component in an organism’s biochemical and metabolic functions. This isespecially important for the brain. When the brain is deprived of O2), injury and life-threatening situations can occur. We can learn a great deal from a neural system that has evolved to combat hypoxia (low oxygen levels) and anoxia (no oxygen) in the brain. During my summer research project, I focused on the Lithobates catesbeianus, most commonly known as the American bullfrog.

Though respiratory network activity ceases during severe hypoxia, the network is able to generate again upon reintroduction of O2 and return to its normal functions (Winmill RE, et al). How is this possible? By building upon background information, we hypothesized that inhibition of ATP synthesis through different routes in the presence of oxygen would resemble the anoxic response if metabolic failure contributes to the network shutdown. To test this hypothesis, I focused on the bullfrog’s cranial nerves and used them to record electrical brain activity. Depending on which part of the experiment I completed each day, a certain drug was administered to the brainstem to analyze its effects. Our findings showed that neurons in the frog brain can survive without ATP synthesis for extended periods of time with no impact on function after reoxygenation, suggesting that metabolism is an important contributor to allowing bullfrogs to survive anoxia.

Realities of Research

Artificial brain fluid on magnetic stirrer, Dr. Joseph Santin lab, UNC Greensboro

Research is one of the most important aspects of human advancement and development. Unsurprisingly, scientists have great responsibilities that pose many challenges. One of the biggest challenges of a scientist is the reality that research is unpredictable. Although my lab’s results generally supported my hypothesis, there were days when experiments did not work and I had to backtrack, figure out my mistakes and start over. Unpredictable results can also mean that your day is too unpredictable. I had to take initiative for what needed to be done and be responsible enough to make it happen. It surprised me that I wasn’t told what I needed to do every day, minute by minute. I had to take charge of my project. This is especially true for scientists who may be doing novel research or research not found in the available literature. While this aspect of research is challenging, it is also fun to brainstorm the best way to go about your research. For instance, I had to categorize and analyze the data collected of neuronal motor output of the bullfrogs.; This had not been done before and Ihad to learn analysis techniques as well as use my creativity and knowledge to create a system of categorization. Being able to highlight my passion for problem solving and creativity was what kept me so interested in research.

Life as a Scientist

White coats, colorful chemicals and a crazy, wild lab. This “Hollywood stereotype” may be what comes to mind for some people when they think about a scientist. As a first-generation minority, that’s what came to my mind as well. I had not been exposed to research as a career and only knew what I saw in the media. It was not until I received the 2019 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) fellowship that I was able to understand the life of a scientist—and it was drastically different from what I expected.

In my experience, there is no “day-to-day life” of a scientist. Every day was different. One day I may have dissected a brain from a frog, while the next, I analyzed data and the day after, I was expanding my knowledge further by reading scientific literature. Some days, I had lots of hands-on work and was really busy and other days, I had plenty of downtime. While this dynamic work environment was fun and exciting, it was also very challenging for me. I was fortunate enough, and will be forever grateful, for being placed within a lab team that helped me work through my hesitations this summer. My team consisted of another undergraduate student, a masters student and my principal investigator. Having these three people in my circle allowed me to transcend the expectations I had for myself. I hope that I can one day use this experience to expose young, first-generation minorities to what it means to be a scientist early in their careers. This is a tool I wish I had when I was younger.

Reference:

Winmill RE, et al. “Development of the Respiratory Response to Hypoxia in the Isolated Brainstem of the Bullfrog Rana Catesbeiana.” The Journal of Experimental Biology, vol. 208, 2005, pp. 213–22

Bianca Okhaifor is a senior at the University of North Carolina at Greensboro. She is a 2019 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working in Dr. Joseph Santin’s lab at the University of North Carolina at Greensboro. Bianca’s fellowship is funded by the APS and a grant from the National Heart, Lung and Blood Institute (Grant #1 R25 HL115473-01). After graduation, Bianca plans to pursue a career as a physician and clinical researcher to focusing on her passion of working specifically with minority children with little to no access to healthcare.

Beats & Breathing
Thomas Asama
Senior
Human physiology major
University of Iowa

My Research Project

Healthy amounts of oxygen are necessary for almost every tissue in the body. Refined mechanisms function to keep oxygen levels within healthy and functioning ranges. A key player in this oxygen regulation, known as the peripheral chemoreflex, acts to sense oxygen in the blood by way of the carotid bodies. Carotid bodies are small structures located next to the carotid arteries in the neck. When the carotid bodies sense that oxygen levels have fallen below normal values, the body responds by activating the sympathetic nervous system (SNS).

The SNS responds to many different bodily stressors and works to increase oxygen uptake to restore oxygen levels. Diseases, however, can disturb this carefully calibrated system. In obstructive sleep apnea (OSA), for example, the airway becomes blocked periodically during sleep, resulting in episodic cessations of breathing and consequential drops in oxygen levels. These frequent periods of low oxygen can cause two issues: first, increased stimulation of the carotid bodies also increased their sensitivity so that normally nonproblematic decreases in oxygen can trigger their activity; second, increased frequency of low oxygen periods and increased sensitivity of the carotid bodies result in an overactive SNS.

The SNS is one of the body’s general response pathways and works to increase oxygen levels while simultaneously increasing blood pressure. Overactivity of the SNS can lead to chronic high blood pressure which places individuals at risk of stroke, heart failure and many other health issues. By looking for possible ways to alleviate these issues, some animal research has suggested that the molecule nitric oxide (NO) has the ability to desensitize the carotid bodies. Additionally, significant literature has demonstrated that supplementing nitrate (NO3) serves as a way to increase NO availability in the body. Our study intends to assess if supplementation of nitrate in the form of beetroot juice has the ability to decrease the sensitivity and over-responsiveness to low oxygen levels in patients with OSA. Beetroot juice is a relatively cheap and readily available supplement and provides an easily accessible treatment for the general population. If a strong correlation is found, this study will open the field to further research projects pursuing beetroot juice supplementation as adjunct therapy to decrease high blood pressure in the OSA population.

Realities of Research

Research is the epitome of the ability to be dynamic; no complication or problem has one solution. A general image of research provides an image of a lab coat-clad scientist in a sterile silver lab with seemingly perfect and exact run experiments. However, while strongly ordered and rational, the research was often far more less sterile than I had originally planned. Because I was working with human research, a large part of my time in the lab was dependent on recruiting subjects. We had various study days throughout the summer working on collecting data for analysis. I quickly realized there wasn’t one way to view or process our results. I spent many hours spent organizing and reorganizing data in excel, trying to find the best way to compare the different data sets we had been collecting. As the summer went on, I found cleaner and clearer ways to assess and group the data we collected. Ultimately, a large portion of research functions as a product of experience. This summer’s fellowship provided significant time where I could devote myself specifically to this end.

Life as a Scientist

Some children say they want to be an astronaut or a ballerina, and then the nerdier contingent always goes for scientist. Yet, it is seldom true that we know what that kind of life entails. I was amazed by the endless room for growth. On a broader level, there was a vast range of autonomy working and planning as a scientist. What were the next steps? How did today’s data play into the future’s experiments? Each possibility demanded a pursuit of deeper knowledge and expertise in the field. I had the opportunity to attend several research presentations throughout the summer and was constantly amazed by the level at which the professors and researchers considered and analyzed the presentations.

While the opportunity to learn was constant, I was not a fan of the variability of pace in the lab. A big part of this is unique to human research, but the recruitment process meant that some weeks we had no studies and others we had seven or eight. This made it difficult to routinize my work, as each week was different from the last. Nonetheless, during my time in the lab, I had significant opportunities to discuss the content and implications of our research with others. Having this opportunity to discuss physiology solidified my understanding and clarified my misunderstandings of many topics. Likewise, working as a team, each member made up for and filled the needs of others on the team. In this way, together we strove for excellence and efficiency throughout the summer. 

References:

Beets, Border, Diet [Online]. Prexels. https://www.pexels.com/photo/beets-border-diet-food-533298/ [16 Jul. 2019].

Thomas Asama is in his final year of pursuing a bachelor of science in human physiology at the University of Iowa in Iowa City. His undergraduate research experience has been under the mentorship of Dr. Darren Casey, Human Integrative Cardiovascular Physiology Laboratory in the department of physical therapy and rehabilitation science at the University of Iowa. Thomas received funding for his summer research as an Undergraduate Summer Research Felllow (UGSRF) from the American Physiological Society. After completing his undergraduate studies, Thomas plans to attend graduate school for a doctorate in physical therapy, with hopes of pursuing a career in clinical physical therapy.

PTSD: The Unknown Truth About the Sexes
Touré Jones
Junior, human health major
Emory University

My Research Project

Post-traumatic stress disorder (PTSD) is a debilitating mental illness that heavily impacts an individual’s physical, mental and emotional health. One overlooked, but very important, consequence of this illness is that individuals with PTSD have an increased risk of developing hypertension and cardiovascular disease1. Past research has revealed that those with PTSD have an exaggerated blood pressure and heart rate response and a blunted heart rate variability response to acute mental stress1. While these studies have improved our understanding of PTSD and the physiological effects it has, they don’t highlight a very important factor: the possibility that it affects men and women differently.

PTSD studies have typically been either all men, or a very few women included in a mostly male population. The research has produced results that primarily focus on male reactivity2, andhas neglected an entire demographic of PTSD victims that seem to have a different response. While men and women have a similar rate of experiencing traumatic events, women are twice as likely to be diagnosed with PTSD3. In addition, healthy premenopausal women have a lower risk of developing cardiovascular disease compared to men, although once diagnosed with PTSD, this risk increases three times, placing the women at higher risk3. Given these biological differences, the purpose of this study was to determine if there is also a sex difference in autonomic and cardiovascular responses to acute mental stress in individuals who have PTSD.

Our study consisted of 33 individuals— 15 women and 18 men—for a total of two visits. The first visit was a screening where we took the volunteers’ vital signs, gave them PTSD surveys to determine the severity of their condition and checked for exclusion criteria to ensure they could be in the study. The second visit was a micro visit, where we recorded experimental data. We measured the study subjects’ blood pressure, heart rate and muscle sympathetic nerve activity at baseline, then those same recordings during three minutes of mental stress. Beat-to- beat blood pressure was recorded using a continuous noninvasive arterial pressure (CNAP) monitor and heart rate was recorded via an electrocardiogram (EKG). Muscle sympathetic nerve activity (MSNA) was recorded via the microneurography procedure. Mental arithmetic served as our mental stressor: the participants subtracted a given number from a numbered index card continuously for three minutes while a “coach” was pressuring them to give an answer as quickly as possible. 

At baseline, measurements for age, body mass index, clinician-administered PTSD scale (CAPS) and PSTD checklist–military version (PCLM) survey scores, blood pressure and heart rate variability were all comparable between the sexes. However, MSNA was significantly different. This was a very interesting find, as we were not anticipating this result. In healthy populations, men have a higher MSNA at rest than women. Based on this data, it seems that women with PTSD have a higher resting MSNA than men. In response to mental stress, systolic arterial pressure was higher in women than men, while diastolic arterial pressure was comparable between the two groups. In addition, heart rate seemed to be higher in women than men, but had not reached significance, although MSNA in response to mental stress was significantly higher in women compared to men. Even more interesting was the root mean square of the successive differences (RMSSD), the time domain measurement of parasympathetic nervous system activity, was comparable between both groups, but the high frequency domain for parasympathetic response showed women having a decreased response to mental stress than men.

In conclusion, resting MSNA was significantly higher in the women than the men. Systolic arterial pressure reactivity to mental arithmetic as higher in women with PTSD compared to men, while diastolic arterial pressure reactivity was comparable between the groups. Heart rate was comparable between women and men with PTSD. MSNA reactivity to mental stress was higher in women than men while heart failure response was blunted in women compared to men suggesting greater dysregulation of the autonomic nervous system in women with PTSD. RMSSD was comparable between men and women in response to mental stress.

In summary, women with PTSD in our study have an increased blood pressure and sympathetic response in addition to a blunted parasympathetic response to acute mental stress. These results provide insight into the mechanisms that are associated with a higher risk of cardiovascular disease in women with PTSD.

Realities of Research

Doing research in a lab was very different from my high school research experiences. For one, this was a clinical lab, so I was working with people every day, which was a rewarding experience. Also, my lab team was made up of very intelligent, cohesive and welcoming individuals, so during every study I was able to learn something new while having a good time. I also had to learn how to set up the lab for the studies we would be conducting, so I had to understand the procedure being performed and how to prepare for it. For example, one procedure we performed was microneurography— a qualified lab member inserted a tungsten electrode into the participants’ peroneal nerve to record sympathetic activity. 

What surprised me about the experience was how often research doesn’t go as planned, especially when working with people. Some study participants wouldn’t come in to the lab as scheduled, or if they did, they didn’t want to go forward with certain procedures for a variety of reasons. Because of this, some patients didn’t have all of the data I anticipated collecting, but that was just a part of the research process.

As for our results, it was very rewarding to see my hard time and effort come to fruition. Some of the results I expected, but others I wasn’t expecting at all. Honestly, each result made the experience all the more exciting.

Life as a Scientist

Life this summer was challenging, but rewarding. I experience many exciting things that have provided me with good memories. The feeling that I felt once I formed graphs based on my data was great and was the best part of the experience; it was the result of my hard work and dedication to my project.

The worst part of the experience would have to be the hours I spent trying to understand certain topics by myself. While learning more about what I am doing interested me, there was some information I needed to know but took me a little while to grasp, which often annoyed me. However, once I did understand it, the passion I had for my project increased. Finally, my lab team was instrumental in me developing this project, especially my mentor. Her mentorship has taught me so much during the weeks I spent with her this summer and I am excited to learn even more.

References:

    1. Edmondson D, von Kanel R. Post-traumatic stress disorder and cardiovascular disease. The Lancet Psychiatry 2017;4:320-9.
    2. Park, J., Marvar, P. J., Liao, P., et al. (2017). Baroreflex dysfunction and augmented sympathetic nerve responses during mental stress in veterans with post-traumatic stress disorder. The Journal of Physiology, 595(14), 4893–4908. doi:10.1113/JP274269
    3. Kubzansky LD, Koenen KC, Jones C, Eaton WW. A prospective study of posttraumatic stress disorder symptoms and coronary heart disease in women. Health psychology : Official Journal of the Division of Health Psychology, American Psychological Association 2009;28:125-30.

Touré Jones is a junior majoring in human health at Emory University in Atlanta. He is a 2019 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working in Dr. Jeanie Park’s lab also at Emory University. Touré’s fellowship is funded by APS and a grant from the National Heart, Lung, and Blood Institute (Grant #1: R25 HL115473-01). After graduation, Touré plans on attending medical school to pursue his dreams of being a physician.

Some Serious Monkey Business
Lucas Barrett
Senior, biology major
University of Kentucky

My Research Project

My research project was focused on using the African green monkey as a translational animal model for human disease. I was particularly interested in the gene that encodes for a protein known to be a component of cholesterol transport. The protein also has a natural ability to protect against certain parasites. In humans, two different versions of this gene have been associated with early-onset kidney disease. Our lab found a version of this gene in the African green monkey that is associated with high blood pressure, and I continued this discovery by looking for additional monkey species that have a similar version of the gene.

In order to find more monkeys with the insertion, I took tissue samples from animals at our vivarium, from which I then extracted DNA.  I also followed the kidney function of monkeys with different variations of the gene to discover whether it was associated with kidney disease in the African green monkey. I assessed kidney function by measuring chemical levels from blood and urine samples which helped determine whether this gene was a marker for kidney disease in this animal model. The main goal of this summer’s project was to identify the African green monkey as a model to study this specific type of kidney disease in humans through the investigation of alternate versions of this gene.

Realities of Research

Doing research has been both the most rewarding and most frustrating endeavor that I have ever undertaken. Being engaged in new scientific discovery is exciting, but the time and effort that go into research can be exhausting. A particularly difficult part of research this summer was troubleshooting why an experiment or laboratory technique did not work as expected.

I was most surprised at how acceptable and common it is to be wrong. Amazingly, in the scientific community, there is nothing inherently bad about being wrong as long as you learn from and adapt to the information you uncover. Working as part of a team in the lab was one of the best parts of this experience. Being able to discuss different projects and rely on others for help as they rely on you was enjoyable, and pushed me to be an expert on my assigned tasks. At the same time, I learned to be competent and well-versed in the other tasks going on in the lab.

Life as a Scientist

Working and living as a scientist for the summer was an experience full of joy and fun, but I also learned a lot that I didn’t know about the day-to-day life conducting research. I was fortunate to go for three weeks to the island of Saint Kitts in the Caribbean islands to do field work that involved collecting data and samples for the lab.

Most people I told about this trip assumed that a stay in the Caribbean would be laid back and more akin to a vacation than a work trip, but nothing could have been further from reality. Out of the 20 days we were on the island, we only took one day completely off from work and I did not anticipate how tiring it would be to work outside in a tropical climate. Despite falling into bed most days from exhaustion, I learned more every day and was fascinated by working with our live animal model; instead of simply working with blood, urine and tissue in the lab.

Lucas Barrett is a senior majoring in biology at the University of Kentucky in Lexington. He is a 2019 Undergraduate Summer Research Fellow (UGSRF) working in the laboratory of Dr. Jeffrey Osborn at the University of Kentucky.  Lucas’ fellowship is funded by the American Physiological Society. After graduation, Lucas plans to pursue a career as a physician-scientist studying human disease. He plans to enroll in a medical scientist program after finishing his degree at the University of Kentucky.

PoWeRful mice and the effect of satellite cell depletion
Alec Dupont
Junior, biomedical science major
Auburn University

My Research Project

My project involved examining the adaptation of skeletal muscle to resistance exercise in mice that had been depleted of muscle stem cells (satellite cells). Generally, muscle growth is accompanied by an increase in protein synthesis and the differentiation of satellite cells into muscle nuclei. During this project, we examined if growth happens without the addition of satellite cells into muscle. As certain clinical populations have reduced satellite cell content and muscle mass, our project aimed to provide insights into how muscles respond to a growth stimulus with the loss of this cell population.

We used Progressive Weighted Wheel running (PoWeR) as a model for resistance exercise. PoWeR involves voluntary running activity of the mice in weighted running wheels. The weight placed on the running wheel is gradually increased over the course of four to eight weeks, overloading the musculature and causing a growth response called muscle hypertrophy. Using a genetic mouse model that allowed for the selective depletion of satellite cells, we compared sedentary- and resistance-exercised mice in groups of satellite cell-replete (vehicle treated) and -depleted (tamoxifen treated) mice. We compared muscle hypertrophy and other physiological adaptations between groups to determine the effects of satellite cell depletion. At the completion of this project, we hoped to gain a further understanding of the role satellite cells play in muscle growth.

Realities of Research

My main focus for the summer was using muscle tissue from the PoWeR mice, and making it possible to obtain data and useful information. I accomplished this through immunohistochemistry, a laboratory technique where we cut cross sections of the muscle and stain them for proteins of interest. This staining allowed us to visualize the sections under the microscope, image them and quantify the images using different forms of software. This technique presented certain challenges because the tissue must be carefully prepared and stored to prevent degradation. Poor quality tissue introduced variability outside of what is normal to the mice models. For example, having to overcome challenges and work to optimize a stain meant visualizing newly formed RNA in muscle nuclei. The stain can appear too dull and the quality would not be high enough to draw conclusions unless the procedure was optimized. Overcoming these challenges provided stunning images and reliable data. We found that although satellite cells were not absolutely required for muscle growth in response to weighted wheel running, there was a decrease in growth in the satellite cell depleted mice.

Life as a Scientist

The day-to-day life of a research scientist presented me with a constantly changing experience that was more engaging than the traditional classroom setting. There was always a new aspect of the project to investigate. It was incredibly satisfying to see your work come together in data that tell a cohesive story. The process of getting there was occasionally tedious though. For example, we’d normalize our data to the number of fibers in the muscle cross section and when the software couldn’t count for us, we were forced to count by hand. When the sections were between 600 and 800 fibers in a study with 48 mice, that part of research tended to drag. But that was only a minor inconvenience to a necessary bump in the road towards a satisfying research project.

Alec Dupont is a junior at Auburn University in Auburn, Alabama, studying biomedical science. He is a 2019 Undergraduate Summer Research Fellow (UGSRF) working under Dr. Charlotte Peterson at the Center for Muscle Biology at the University of Kentucky in Lexington. Alec’s work is funded by the American Physiological Society’s UGSRF program and a grant from the National Institute of Health to Dr. Charlotte Peterson and Dr. John McCarthy (AR060701).

Cycle Training promotes bone growth following Spinal Cord Injury
Jayachandra Kura
Junior, Applied Physiology and Kinesiology
University of Florida
2019 UGSRF Fellow

My Research Project

Figure 1. Transverse view of long bone with red ROI

This past summer, I worked in Dr. Joshua F. Yarrow’s research lab at the Malcom Randall Department of Veteran Affairs Medical Center. Dr. Yarrow’s lab explores the effectiveness of pharmacologic and exercise treatments following spinal cord injury (SCI). For the specific SCI we studied, the posterior end of the 9th thoracic vertebrae was surgically removed, exposing the spinal cord underneath. A machine delivered an impact causing hindlimb paralysis. My research  used Sprague-Dawley rats that were given either a 1) SCI, 2) surgical control (SHAM), 3) SCI + Bodyweight Supported Treadmill Training, or 4) SCI + Passive Bicycle Training. We scanned the distal femurs at baseline, two weeks and four weeks after SCI using a micro tomography (microCT) scanner.

In order to observe the effect of each treatment on the spongy cancellous bone, a technician would individually draw a region of interest (ROI) in the transverse view of the femur (Fig. 1) to include the internal trabeculae while excluding both the growth plate and solid cortical bone. However, repeating this on more than 100 slices for every sample at every time point is very time intensive. Instead, I worked to adapt a registration procedure for the spinal cord injury model. The registration was created by using two scans at different time points are aligning them in 3D. An ROI was created at baseline and then applied to the two-week and four-week scans, reducing the amount of labor required. I then compared the data from registered images to data from nonregistered images. I also helped to develop a script that allowed the computer to automatically draw the ROI with minimal manual correction, which further improved efficiency.

Realities of Research

Figure 2. Spinal Cord Injury Model. However, instead of a contusion by weight drop, there is a machine performing the impact.

My introduction into research has definitely been equal parts trying and gratifying—trying in the sense that every solution I created seemed to raise a host of other questions that needed to be addressed. I remember when I finally figured out how to register two different time point images, but I then needed to decide what size volume of interest (VOI) to use so the computer knew which landmarks to use to align the two different bones. Intuitively, using a large VOI should provide more datapoints for the computer to use. Doing so caused the solid cortical borders to be well-aligned, but the internal structures weren’t. Repeating this with multiple samples yielded the same results, which suggested that, in bone remodeling, an individual bony landmark’s relative position to the cortical border changes with time. However, using a small VOI caused poor alignment of the two images. This seemed counterintuitive, so when I looked over previous scans of SCI samples, I observed a trend of severe bone loss occurring below the injury site. The registration procedures outlined in the literature couldn’t directly translate to a SCI model as those outlined procedures required clear internal bony landmarks. Without these data points, the automatic registration software couldn’t produce an accurate alignment.

In this seemingly never-ending cycle of forming new ideas only to eliminate them later on, I didn’t come any closer to developing a script, but I did develop a lot of patience and perseverance. I found research to be inherently challenging, but the setbacks I encountered only made me grow as a person and researcher, and ultimately, made the end result of creating a “mostly” functioning protocol all that more rewarding. I’ve also come to realize that there is never a true “end” in research as there arealways things that can be improved or new questions that can be asked. This opportunity for continual growth was really exciting and intrinsically motivating.

Life as a Scientist

Compared to my past work experiences, research has by far been the most enjoyable. Never did I have a bout of the “Sunday scaries,” where I was enveloped with the existential dread of going to work the following day. In contrast, my work environment was low-stress and was dictated entirely by my own drive and will to work. The lab was filled with diverse, interesting individuals and I enjoyed the conversations I had and the relationships I formed with my labmates. Although there was always monotonous data entry, most of the work I did within the lab was challenging and fun. I always felt the work I was doing was meaningful.

I recall a conversation I had with my labmate who’d recently graduated: I had jokingly asked what it was like not having class. He laughed and said, “I spent the last four years—every fall, spring and summer semester—taking classes and working here at the hospital. If you think about it, when you’re an undergraduate, you’re basically working 70+ hours a week with all the stuff you do, so you really never have to think about anything except for school. Now that I’ve graduated and work 40 hours a week here in the lab, my work ends when I leave. But I remember going home and sitting on my couch not knowing what to do with myself, thinking, ‘Man, time to find some hobbies.’” Being out of school, if only briefly, allowed me to finally begin to appreciate this. Now sitting on my own couch trying to find things to do, I’ve found this freedom to be exciting and paralyzing.  I definitely feel that the physician/scientist career path is like a pipeline and there’s constant pressure to continue moving towards the end. To be honest, I haven’t put much thought into the adult I want to be outside of my career or really explored the things I find fulfilling. I’m just thankful for the opportunity to have had these experiences, both in and out of the lab, and believe that this summer was largely beneficial for my growth not only as a researcher, but also as a person.

References:

L Arsuaga, J & Villaverde, Valentín & Quam, Rolf & Martínez, I & M Carretero, J & Lorenzo, Carlos & Gracia, Ana. (2013). Arsuaga et al. 2007.

“Establishment of a Rat Model of Spinal Cord Injury (SCI).” Neural Regeneration Research, www.nrronline.org/viewimage.asp?img=NeuralRegenRes_2016_11_12_2004_197145_f1.jpg.

Jayachandra Kura is a junior majoring in applied physiology and kinesiology and minoring in Japanese at the University of Florida in Gainesville. He is a 2019 American Physiology Society Undergraduate Summer Research Fellow (USGSRF) working in Dr. Joshua F. Yarrow’s lab at the North Florida/South Georgia Medical Center in Gainesville, Fla. Jayachandra’s fellowship is funded by the American Physiological Society and the Department of Veterans Affairs. After graduation, Jayachandra plans to pursue a career as a physician scientist.