Monthly Archives: November 2019

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.