Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Lecture (Page 1 of 13)

Game-Changing App Explores Conservation’s Future

In the first week of February, students, experts and conservationists from across the country were brought together for the second annual Duke Blueprint symposium. Focused around the theme of “Nature and Progress,” this conference hoped to harness the power of diversity and interdisciplinary collaboration to develop solutions to some of the world’s most pressing environmental challenges.

Scott Loarie spoke at Duke’s Mary Duke Biddle Trent Semans Center.

One of the most exciting parts of this symposium’s first night was without a doubt its all-star cast of keynote speakers. The experiences and advice each of these researchers had to offer were far too diverse for any single blog post to capture, but one particularly interesting presentation (full video below) was that of National Geographic fellow Scott Loarie—co-director of the game-changing iNaturalist app.

iNat, as Loarie explained, is a collaborative citizen scientist network with aspirations of developing a comprehensive mapping of all terrestrial life. Any time they go outside, users of this app can photograph and upload pictures of any wildlife they encounter. A network of scientists and experts from around the world then helps the users identify their finds, generating data points on an interactive, user-generated map of various species’ ranges.

Simple, right? Multiply that by 500,000 users worldwide, though, and it’s easy to see why researchers like Loarie are excited by the possibilities an app like this can offer. The software first went live in 2008, and since then its user base has roughly doubled each year. This has meant the generation of over 8 million data points of 150,000 different species, including one-third of all known vertebrate species and 40% of all known species of mammal. Every day, the app catalogues around 15 new species.

“We’re slowly ticking away at the tree of life,” Loarie said.

Through iNaturalist, researchers are able to analyze and connect to data in ways never before thought possible. Changes to environments and species’ distributions can be observed or modeled in real time and with unheard-of collaborative opportunities.

To demonstrate the power of this connectedness, Loarie recalled one instance of a citizen scientist in Vietnam who took a picture of a snail. This species had never been captured, never been photographed, hadn’t been observed in over a century. One of iNat’s users recognized it anyway. How? He’d seen it in one of the journals from Captain James Cook’s 18th-century voyage to circumnavigate the globe.

It’s this kind of interconnectivity that demonstrates not just the potential of apps like iNaturalist, but also the power of collaboration and the possibilities symposia like Duke Blueprint offer. Bridging gaps, tearing down boundaries, building up bonds—these are the heart of conservationism’s future. Nature and Progress, working together, pulling us forward into a brighter world.

Post by Daniel Egitto

 

 

How A Bat’s Brain Navigates

Most of what we know about how the hippocampus, a region of the brain associated with memory formation and spatial representations, comes from research done on rodents. Rat brains have taught us a lot, but researchers in Israel have found an interesting alternative model to understanding how the hippocampus helps mammals navigate: Bats.

The Egyptian fruit bat proved the perfect subject for studies of mammalian navigation.

Weizmann Institute neurophysiologist Nachum Ulanovsky, PhD, and his team have looked to bats to understand the nuances of navigation through space. While previous research has identified specific cells in the hippocampus, called place cells, that are active when an animal is located in a specific place, there is not much literature describing how animals actually navigate from point A to point B.

Nachum Ulanovsky

Ulanovsky believes that bats are an ingenious model to study mammalian navigation. While bats have the same types of hippocampal neurons found in rats, the patterns of bats’ neurons’ firings more closely match that of humans than rats do.

Ulanovsky sought to test how bats know where they are going. Using GPS tracking equipment, his team found that wild bats that lived in a cave would travel up to 20 kilometers to forage fruit from specific trees. Night after night, these bats followed similar routes past perfectly viable food sources to the same tree over and over again.

The understanding of hippocampal place cells firing at specific locations doesn’t explain the apparent guided travel of the bat night after night, and other explanations like olfactory input do not explain why the bats fly over good food sources to their preferred tree.

The researchers designed an experiment to test how bats encode the 3D information necessary for this navigation. By letting the bats fly around and recording brain activity, Ulanovsky and team found that their 3D models are actually spherical in shape. They also found another type of hippocampal cells that encode the orientation the bat is facing. These head direction cells operate in a coordinate system that allows for a continuity of awareness of its orientation as the animal moves through space.

http://www.cell.com/cms/attachment/2091916945/2076305003/gr1_lrg.jpg

Ulanovsky found bats relied on memory to navigate toward the goal.

To understand how the bats navigate toward a specific goal, the researchers devised another experiment. They constructed a goal with a landing place and a food incentive. The bat would learn where the goal was and find it. In order to test whether the bats’ ability to find the goal was memory-based, or utilized the hippocampus, the researchers then conducted trials where the goal was hidden from the bats’ view.

To test whether the bats’ relied on memory, the Ulvanosky team measured the goal direction angle, or the angle between the bat’s head orientation and the goal. After being familiarized with the location of the goal, the bats tended toward a goal-direction angle of zero, meaning they oriented themselves toward the goal even when the goal was out of sight.

Continued research identified cells that encode information about the distance the bat is from the goal, the final piece allowing bats to navigate to a goal successfully. These hippocampal cells selectively fire when the bat is within specific distances of the goal, allowing for an awareness of location over distance.

While Ulanovsky and his team have met incredible success in identifying new types of cells as well as new functions of known cells in the hippocampus, further research in a more natural setting is required.

“If we study only under these very controlled and sterile environments, we may miss the very thing we are trying to understand, which is behavior,” Ulanovsky concluded.

By Sarah Haurin

Dopamine, Drugs, and Depression

The neurotransmitter dopamine plays a major role in mental illnesses like substance abuse disorders and depressive disorders, as well as a more general role in reward and motivational systems of the brain. But there are still certain aspects of dopamine activity in the brain that we don’t know much about.

Nii Antie Addy and his lab are interested in the role of dopamine in substance abuse and mood disorders.

Duke graduate Nii Antie Addy, PhD, and his lab at Yale School of Medicine have been focusing on dopamine activity in a specific part of the brain that has not been studied: the ventral tegmental area (VTA).

To understand the mechanisms underlying this association, Addy and his team looked at cue-induced drug-seeking behavior. Using classical conditioning, rats can be trained to pair certain cues with the reward of drug administration. When a rat receives an unexpected award, dopamine activity increases. After conditioning, dopamine is released in response to the cue more  than to the drug itself. Looking at the patterns of dopamine release in rats who are forced to undergo detoxification can thus provide insight into how these cues and neurotransmitter activity relate to relapse of substance abuse.

When rats are taught to self-administer cocaine, and each administration of the drug is paired with the cue, after a period of forced detoxification, the rodents continue to try to self-administer the drug, even when the drug is withheld and only the cue is presented. This finding again demonstrates the connection between the cue and drug-seeking behavior.

Studying the activity in the VTA gave additional insights into the regulation of this system. During the period of abstinence, when the rodents are forced to detox, researchers observed an increase in the activity of cholingergic neurons, or neurons in the brain system that respond to the neurotransmitter acetylcholine.

Using these observations, Addy and his team sought to identify which of the various receptors that respond to acetylcholine can be used to regulate the dopamine system behind drug-seeking behaviors. They discovered that a specific type of acetylcholine receptor, the muscarinic receptor, is involved in more general reward-seeking behaviors and thus may be a target for therapies.

Using Isradipine, a drug already approved by the FDA for treatment of high blood pressure, Addy designed an experiment to test the role of these muscarinic receptors. He co-opted the drug to act as a calcium antagonist in the VTA and thus increase dopamine activity in rodents during their forced detox and before returning them to access to cocaine. The outcome was promising: administration of Isradipine was associated with a decrease in the coke-seeking behavior of rodents then placed in the chamber with the cue.

The understanding of the role of cholinergic neurons in regulation of dopamine-related mental illnesses like substance-abuse also contributes insights into depressive and anxiety disorders. If the same pathway implicated in cue-induced drug-seeking were involved in depressive and anxious behaviors, then increasing cholinergic activity should increase pro-depressive behavior.

Addy’s experiment yielded exactly these results, opening up new areas to be further researched to improve the treatment of mood disorders.

Post by Sarah Haurin

 

Morphogenesis: All Guts and Morning Glories

What is morphogenesis? Morphogenesis examines the development of the living organisms’ forms.

It also is an area of research for Lakshminarayanan Mahadevan, Professor of Applied Mathematics, Organismic and Evolutionary Biology and Physics at Harvard University. On his presentation in the Public Lectures Unveiling Math (PLUM) series here at Duke, he credited the beginnings of morphogenesis to D’Arcy Wentworth Thompson, author of the book On Growth and Form.

Mathematically, morphogenesis focuses on how different rates of growth change the shapes of organisms as they develop. Cell number, cell size, cell shape, and cell position comprise the primary cellular factors of multicellular morphogenesis, which studies larger structures than individual cells and is Mahadevan’s focus.

Effects on tissues appear through changes in sizes, connectivities, and shapes, altering the phenotype, or the outward physical appearance. All these variables change in space and time. Professor Mahadevan presented on morphogenesis studies that have been conducted on plant shoots, guts, and brains.

Research on plant shoots often concentrates on the question, “Why do plant shoots grow in such a wide variety of directions and what determines their shapes?” The picture below shows the different postures appearances of plant shoots from completely straight to leaning to hanging.

Can morphogenesis make sense of these differences? Through mathematical modeling, two stimuli for shoots’ shapes was determined: gravity and itself. Additionally, elasticity as a function of the shoots’ weight plays a role in the mathematical models of plant shoots’ shapes which appear in Mahadevan’s paper co-written with a fellow professor, Raghunath Chelakkot. Mahadevan also explored the formation of flower and leaf shapes with these morphogenesis studies. 

Over twenty feet of guts are coiled up inside you. In order to fit these intestines inside the mammals, they must coil and loop. But what variables determine how these guts loop around? To discover the answer to this question, Mahadevan and other researchers examined chick embryos which increase their gut lengths by a factor greater than twenty over a twelve-day span. They were able to create a physical model using a rubber tube sewn to a sheet that followed the same patterns as the chicks’ guts. Through their observation of not only chicks but also quail and mice, Mahadevan determined that the morphogenesis of the guts has no dependence on genetics or any other microscopic factors.

Mahadevan’s study of how the brain folds occurs through MRI images of human fetal development. Initially, barely any folding exists on fetal brains but eventually the geometry of the surrounding along with local stress forms folds on the brain. By creating a template with gel and treating it to mimic the relationship between the brain’s gray matter and white matter, Mahadevan along with other researchers discovered that they could reproduce the brain’s folds. Because they were able to recreate the folds through only global geometry and local stress, they concluded that morphogenesis evolution does not depend on microscopic factors such as genetics. Further, by examining if folding regions correlate with the activity regions of the brain, questions about the effect of physical form on abilities and the inner functions of the brain.

  

     

On a Mission to Increase Exercise

Dr. Zachary Zenko of the Center for Advanced Hindsight at Duke is on a mission to get people to exercise. He shared this mission and his research aimed at achieving this mission at Duke’s Exercise and the Brain Symposium on December 1st.

Dr. Zenko started out with a revealing statistic: Only 1 in 10 people meet the United States activity guidelines for exercise. While I wasn’t completely shocked at this fact as the U.S. is known for its high rates of obesity and easy access to fast-food, I was definitely eager to learn more about how Dr. Zenko planned to fight this daunting statistic.

Next, Dr. Zenko pointed out a common assumption in exercise psychology: if people know how good exercise is for them, they will exercise. However, this hasn’t proven to be true. Most people already know that they should be exercising, but don’t. And those that do often quickly drop out.

Then Dr. Zenko began to break down Dual-Process Theory in Behavioral Economics. Type 1 Processes are those that are fast and non-conscious, while Type 2 Processes are those that are controlled and conscious. While research on exercise usually focuses on Type 2 processes, Zenko believes that we must focus on both.

Ideally, exercise would involve the affect heuristic, which is a mental shortcut in which an emotional response drives an individual. This heuristic involves Type 1 processes. Dr. Zenko’s goal was to shift away from only considering Type 2 processes, and instead focus on using Type 1 processes to make exercise more appealing.

How did he propose doing this? By continually decreasing the difficulty of exercise. By changing the slope of the intensity of a workout and having a continually declining heart rate, exercisers could have a more pleasant experience. In addition, this positive experience could influence memory and make an individual more likely to exercise in the future.

Dr. Zenko put this hypothesis to the test by having unfit adults exercise while continually decreasing the intensity throughout the workout. While test subjects exercised, he measured the amount of pleasure experienced by asking “How do you feel right now?” at certain intervals. This new exercise method  has the most potential when starting at the highest intensity levels because it leaves more room to change the slope of the workout intensity throughout, leading to an overall more pleasurable workout.

Looking forward, this new method of exercise could possibly change the way we think about exercise. It may not only involve doing the right amount of exercise, but also doing the right kind of exercise that leaves us more likely to exercise in the future. Considering that traditional methods of promoting exercise, such as educating people about its benefits, have not been particularly successful thus far, Dr. Zenko’s method is very exciting.

Dr. Zenko wrapped up his talk by suggesting that people consider exercise prescriptions that are safe, effective, pleasant and enjoyable. As exercise has become a huge part of my weekly routine throughout college, I will definitely take this advice to heart. Maybe even look out for me lowering my intensity during a workout soon in a gym near you?

By Nina Cervantes

How We Know Where We Are

The brain is a personalized GPS. It can keep track of where you are in time and space without your knowledge.

The hippocampus is a key structure in formation of memories and includes cells that represent a person’s environment.

Daniel Dombeck PhD, and his team of researchers at Northwestern University have been using a technique designed by Dombeck himself to figure out how exactly the brain knows where and when we are. He shared his methods and findings to a group of researchers in neurobiology at Duke on Tuesday.

Domeck and his lab at Northwestern are working at identifying exactly how the brain represents spatial environments.

The apparatus used for these experiments was adapted from a virtual reality system. They position a mouse on a ball-like treadmill that it manipulates to navigate through a virtual reality field or maze projected for the mouse to see. Using water as a reward, Dombeck’s team was able to train mice to traverse their virtual fields in a little over a week.

In order to record data about brain activity in their mice as they navigated virtual hallways, Dombeck and his team designed a specialized microscope that could record activity of single cells in the hippocampus, a deep brain structure previously found to be involved in spatial navigation.

The device allows researchers to observe single cells as a mouse navigates through a simulated hallway.

Previous research has identified hippocampal place cells, specialized cells in the hippocampus that encode information about an individual’s current environment. The representations of the environment that these place cells encode are called place fields.

Dombeck and his colleague Mark Sheffield of the University of Chicago were interested in how we encode new environments in the hippocampus.

Sheffield studied the specific neural mechanisms behind place field formation.

After training the mice to navigate in one virtual environment, Sheffield switched the virtual hallway, thus simulating a new environment for the mouse to navigate.

They found that the formation of these new place cells uses existing neural networks initially, and then requires learning to adapt and strengthen these representations.

After identifying the complex system representing this spatial information, Dombeck and colleagues wondered how the system of representing time compared.

Jim Heys, a colleague of Dombeck, designed a new virtual reality task for the lab mice.

In order to train the mice to rely on an internal representation of passing time, Heys engineered a door-stop task, where a mouse traversing the virtual hallway would encounter an invisible door. If the mouse waited 6 seconds at the door before trying to continue on the track, it would be rewarded with water. After about three months of training the mice, Heys was finally able to collect information about how they encoded the passing of time.

Heys indentified cells in the hippocampus that would become active only after a certain amount of time had passed – one cell would be active after 1 second, then another would become active after 2 seconds, etc. until the 6-second wait time was reached. Then, the mouse knew it was safe to continue down the hallway.

When comparing the cells active in each different task, Dombeck and Heys found that the cells that encode time information are different from the cells that encode spatial information. In other words, the cells that hold information about where we are in time are separate from the ones that tell us where we are in space.

Still these cells work together to create the built-in GPS we share with animals like mice.

By Sarah Haurin

Scavenger Receptors in Environmental Lung Disease

“Lung disease causes 15% of deaths worldwide” Kymberly Gowdy explained in her lecture at Duke,  “Clean Up and Clear Out: A Novel Role for Scavenger Receptors in Environmental Lung Disease.”

In her research, she applies her training as an immunologist to analyze immune responses to environmental challenges and their role in lung disease. Gowdy is an Assistant Professor at East Carolina University where her research specifically focuses on scavenger receptors (SRs). SRs are pattern recognition receptors that recognize and bind cellular debris and pathogens. Gowdy’s research focuses on scavenger receptor SR-B1 and SR-CD163.

Kymberly Gowdy of East Carolina University

Kymberly Gowdy of East Carolina University

Her experiments with SR-B1 have shown that knockout mice (mice without the scavenger receptor B1) have increased mortality rates after pulmonary infection, as shown in the figure below. After examining different causes of this increase in mortality, Gowdy and her lab concluded that the cause was an increase in bacterial burden.

The pattern they detected revealed that an increase of bacteria in the blood correlates to both an increase in cytokines (substances secreted by immune cells that create inflammation and respond to infections) and an increase in mortality. Gowdy also associated a decrease in clearance in the lungs with this trend, which explains why pneumonia does not heal and therefore leads to death.

Gowdy’s lab also explored the possibility for a connection between SR-B1 and ozone-induced respiratory and cardiovascular inflammation. She discovered a positive correlation between SR-B1, the oxidization of lipids in the lungs, and pulmonary inflammation. She concludes that SR-B1 expression is protective against air pollutant exposure such as ozone.

Mice lacking SR-B1 (dashed line) only survived two days after an infection challenged their lungs.

Gowdy has also investigated a receptor called SR-CD163 which clears hemoglobin and haptoglobin (Hb-Hp) from the lungs. This receptor protects organs from cell-free hemoglobin preventing damage. When she exposed knockout mice without SR-CD163 to ozone, she discovered an increase in the pulmonary levels of cell-free hemoglobin. Similarly to experiments with SR-B1, the CD163-deficient mice demonstrated patterns of increased lung damage as they experienced increased exposure to ozone.

Through her collaboration with laboratories at Duke, Gowdy has been able to discover that ozone exposure increases the response of pulmonary CD163 in mice and humans.

Gowdy’s work has shown the existence of direct relationships between environmental factors such as ozone and the levels of scavenger receptors such as B1 and CD163 in the lungs. The complex association between immune responses and lung diseases creates an interesting field of research, particularly when explored through the lens of environmental triggers.

Gowdy’s results reveal the intricacy of the immune system. An inflammatory response is meant to protect an individual’s health, but too much immune activation in the lungs can lead to disease.

Post by Lydia Goff.

Long-Term Study Sees the Big Picture of Cannabis Use

Seventy percent of the United States population will have tried marijuana by the age of 30. As the debate on the legalization of the most commonly used illicit drug continues throughout the country, researchers like William Copeland, PhD, and Sherika Hill, PhD, from the Duke Department of Psychiatry and Behavioral Sciences are interested in patterns of marijuana use and abuse in the first 30 years of life.

Marijuana is the most commonly used illicit drug.

The Great Smoky Mountain Study set out in 1992 to observe which factors contributed to emotional and behavioral problems in children growing up in western North Carolina. The study included over 1,000 children, including nearly 400 living on the Cherokee reservation. In addition to its intended purpose, the data collected has proven invaluable to understanding how kids and young adults are forming their relationship with cannabis.

The Great Smoky Mountains Study collected extensive medical and behavioral research from 11 counties in western North Carolina.

Using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and patterns of daily use of the drug, Copeland and Hill found some unsurprising patterns: peak use of the drug is during young adulthood (ages 19-21), when kids are moving out of the home to college or to live alone.

But while most people adjust to this autonomy and eventually stop their usage of the drug, a small percentage of users (7%) keep using into their adulthood. Hill and Copeland have observed specific trends that apply both to this chronic user group as well as an even smaller percentage of users (4%) who begin using at a later stage in life than most people, termed the delayed-onset problematic users.

Looking at the demographics of the various types of users, Hill and Copeland found that males are twice as likely to engage in marijuana use to any extent than females. Of those who do use the drug, African Americans are five times more likely to be delayed-onset users, while Native Americans are twice as likely to decrease their use before it becomes problematic.

For both persistent and delayed-onset problematic users, family instability during childhood was 2-4 times more likely than in non-problematic users.

Persistent users were more likely to have endured anxiety throughout childhood, and delayed-onset users were more likely to have experienced some kind of trauma or maltreatment in childhood than other types of users.

The identification of these trends could prove a vital tool in predicting and preventing marijuana abuse, and the importance of this understanding is evidenced in the data collected that elucidates outcomes of marijuana use.

Looking at various measures of social and personal success, the team identified patterns with a resounding trend: recent use of marijuana is indicative of poorer outcomes. Physical health and financial or educational outcomes displayed the worst outcomes in chronic and delayed-onset users. Finally, criminal behavior was increased in every group that used; in other words, regardless of the extent of use, every group with use of marijuana fared worse than the group that abstained.

The results of Copeland and Hill’s work has important implications as legislators debate the legalization of marijuana. While understanding these patterns of use and their outcomes can provide useful insight on the current patterns of usage, decriminalization will certainly change the way marijuana is manufactured and consumed, and will thus also affect these patterns.
By Sarah Haurin

Who Gets Sick and Why?

During his presentation as part of the Chautauqua lecture series, Duke sociologist Dr. Tyson Brown explained his research exploring the ways racial inequalities affect a person’s health later in life. His project mainly looks at the Baby Boomer generation, Americans born between 1946 and 1964.

With incredible increases in life expectancy, from 47 years in 1900 to 79 today, elderly people are beginning to form a larger percentage of the population. However among black people, the average life expectancy is three and a half years shorter.

“Many of you probably do not think that three and half years is a lot,” Brown said. “But imagine how much less time that is with your family and loved ones. In the end, I think all of us agree we want those extra three and a half years.”

Not only does the black population in America have shorter lives on average but they also tend to have sicker lives with higher blood pressures, greater chances of stroke, and higher probability of diabetes. In total, the number of deaths that would be prevented if African-American people had the same life expectancy as white people is 880,000 over a nine-year span. Now, the question Brown has challenged himself with is “Why does this discrepancy occur?”

Brown said he first concluded that health habits and behaviors do not create this life expectancy gap because white and black people have similar rates of smoking, drinking, and illegal drug use. He then decided to explore socioeconomic status. He discovered that as education increases, mortality decreases. And as income increases, self-rated health increases. He said that for every dollar a white person makes, a black person makes 59 cents.

This inequality in income points to the possible cause for the racial inequality in health, he said.  Additionally, in terms of wealth instead of income, a black person has 6 cents compared to the white person’s dollar. Possibly even more concerning than this inconsistency is the fact that it has gotten worse, not better, over time. Before the 2006 recession, blacks had 10-12 cents of wealth for every white person’s dollar.

Brown believes that this financial stress forms one of many stressors in black lives including chronic stressors, everyday discrimination, traumatic events, and neighborhood disorder which affect their health.

Over time, these stressors create something called physiological dysregulation, otherwise known as wear and tear, through repeated activation of  the stress response, he said. Recognition of the prevalence of these stressors in black lives has lead to Brown’s next focus on the extent of the effect of stressors on health. For his data, he uses the Health and Retirement Study and self-rated health (proven to predict mortality better than physician evaluations). For his methods, he employs structural equation modeling. Racial inequalities in socioeconomic resources, stressors and biomarkers of physiological dysregulation collectively explain 87% of the health gap with any number of causes capable of filling the remaining percentage.

Brown said his next steps include using longitudinal and macro-level data on structural inequality to understand how social inequalities “get under the skin” over a person’s lifetime. He suggests that the next steps for society, organizations, and the government to decrease this racial discrepancy rest in changing economic policy, increasing wages, guaranteeing work, and reducing residential segregation.

Post by Lydia Goff

Creative Solutions to Brain Tumor Treatment

Survival rates for brain tumors have not improved since the 1960s; NIH Image Gallery.

Invasive brain tumors are among the hardest cancers to treat, and thus have some of the worst prognoses.

Dean of the Pratt School of Engineering, Ravi Bellamkonda, poses for his portrait inside and outside CIEMAS.

Displaying the survival rates for various brain tumors to the Genomic and Precision Medicine Forum on Thursday, Oct. 26, Duke professor Ravi Bellamkonda noted, “These numbers have not changed in any appreciable way since the 1960s.”

Bellakonda is the dean of the Pratt School of Engineering and a professor of biomedical engineering, but he is first a researcher. His biomedical engineering lab is working toward solutions to this problem of brain tumor treatment.

Unlike many other organs, which can sacrifice some tissue and remain functional, the brain does not perform the same way after removing the tumor. So a tumor without clearly defined boundaries is unsafe to remove without great risk to other parts of the patient’s brain, and in turn the patient’s quality of life.

Bellakonda hypothesized that brain tumors have characteristics that could be manipulated to treat these cancers. One key observation of brain tumors’ behavior is the tendency to form along white matter tracts. Put simply, tumors often spread by taking advantage of the brain’s existing structural pathways.

Bellakonda set out to build a device that would provide brain tumors a different path to follow, with the hope of drawing the tumor out of the brain where the cells could be killed.

The results were promising. Tests on rats and dogs with brain tumors showed that the device successfully guided out and killed tumor cells. Closer examination revealed that the cells killed were not cells that had multiplied as the tumor grew into the conduit, but were actually cells from the primary tumor.

The Bellamkonda lab’s device successfully guided and killed brain tumors in rats.

In addition to acting as a treatment device, Bellakonda’s device could be co-opted for other uses. Monitoring the process of deep brain tumors proves a difficult task for neurooncologists, and by bringing cells from deep within the tumor to the surface, this device could make biopsies significantly easier.

Although the device presents promising results, Bellakonda challenged his lab to take what they have learned from the device to develop a less invasive technique.

Another researcher in the Bellakonda lab, Tarun Saxena, engaged in research to utilize the body’s natural protection mechanisms to contain brain tumors. Creating scar tissue around tumors can trick the brain into treating the tumor as a wound, leading to immunological responses that effectively contain and suppress the tumor’s growth.

Visiting researcher Johnathan Lyon proposed utilizing electrical fields to lead a tumor to move away from certain brain regions. Moving tumors away from structures like the pons, which is vital for regulation of vital functions like breathing, could make formerly untreatable tumors resectable. Lyon’s 3D cultures using this technique displayed promising results.

Another Bellakonda lab researcher, Nalini Mehta, has been researching utilizing a surprising mechanism to deliver drugs to treat tumors throughout the brain: salmonella. Salmonella genetically engineered to not invade cells but to easily pass through the extracellular matrix of the brain have proven to be effective at delivering treatment throughout the brain.

While all of these therapies are not quite ready to be used to treat the masses, Bellakonda and his colleagues’ work presents reasonable hope of progress in the way brain tumors are treated.

By Sarah Haurin

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