Published by the Students of Johns Hopkins since 1896
April 24, 2024

Science & Technology



Primary visual cortex linked to action timing

The brain regulates nearly everything about us — homeostasis, perception and cognitive function — but how specific brain regions connect and work together is still not perfectly understood. Recently, a team at the Johns Hopkins School of Medicine and the University of Texas-Houston uncovered a previously unknown role of the region that initiates the processing of visual input. The brain’s primary visual cortex, referred to as V1, is responsible for sensing visual information about the world around us. The primary visual cortex, located in the occipital lobe at the back the brain, creates a map of our visual field. This map is then relayed to other areas of brain, which make decisions based on these visual clues and generate a motor response. This is the traditional or canonical view. However, a recent study conducted by Dr. Marshall Shuler and his team implicates the V1 region in more than just visual sensing. The work, published in Neuron, suggests that the V1 primary visual cortex plays a role in making time-based action decisions following visual stimuli. Shuler is an assistant professor within the department of neuroscience at the School of Medicine. In order to investigate the role of V1 in time-based action, Shuler’s team used mice fitted with a special set of goggles capable of presenting a visual stimulus in the form of light and thereby stimulating the V1 region. The mice, thirsty from a lack of water, were given access to a waterspout. Water would flow from the spout at a specific time interval following a light stimulus that was presented in the goggles. Licking the waterspout in the target interval gave the mice a small amount of water as a reward. However, if they timed it incorrectly, they would receive no water. The researchers then investigated whether mice were capable of being trained to receive the most water. That is, could mice learn to wait and time their licks to get the most water after V1 cortex stimulation by visual cues? This allowed the researchers to test the role of the V1 cortex in making time-based action decisions. The team found that mice could indeed be trained to receive the maximal amount of water. With increased trials, the mice gradually learned to time their licks in order to receive the greatest amount. But this result does not relate the V1 cortex to time-based action. In order to test the role of V1 in time-based action making, they measured the activity of V1 neurons during the same waterspout activity. Shuler and his team found that there was a “trial-by-trial correlation between the neural representation of the interval and the action” in 77 out of the 122 neurons they measured. That is, longer V1 neural firing indicated a longer delay between the visual stimulus and the mouse licking the waterspout. But this correlation was only present when mice were given a visual stimulus. In cases of a non-visual stimulus (such as nose-poke entry), there was no such correlation between neural activity and action. This showed that the V1 region may indeed be regulating time-based action following a visual stimulus. The researchers next tried to optogenetically stimulate V1 neurons, seeing whether it was possible to influence the mice’s behavior by presenting different signals to the V1 cortex. Optogenetics, a relatively new development in the field of neuroscience, enables researchers to stimulate genetically-altered neurons with light. Upon optogenetic stimulation of V1 neurons, the researchers found that he was able to change the waiting time in visually stimulated mice. Consistent with his neural activity findings, they found no change in the non-visually stimulated mice upon optogenetic perturbation. The results suggest that the V1 primary visual cortex, traditionally thought of as being the primary visual sensory area in the brain, may actually play a far larger role in making decisions and performing time-based actions. His findings expand our traditional view of the brain as a compartmentalized organ, with each region having a specific function.


The Brain Wave: Neurogenesis as treatment for drug addiction

Drug abuse is a major societal problem. According to the National Institute of Drug Abuse, substance abuse imparts an annual economic burden of more than $600 billion. In particular, cocaine is a powerful stimulant that can cause severe medical consequences, such as heart attacks and strokes. Currently, there is no single medication that can treat cocaine addiction, and psychosocial therapies are often not effective in a significant population of cocaine abusers. Research into how drugs affect the brain is crucial for development of better therapies to reverse addiction and prevent relapse. The most studied cocaine mechanism is how the drug affects the brain’s reward pathway. The reward pathway is a system of neural circuitry that allows us to associate beneficial behaviors with feelings of pleasure. The neurons that are responsible for pleasure form a group called nucleus accumbens (NAc). NAc neurons are activated by a chemical called dopamine, which is released by ventral tegmental area (VTA) neurons. Under normal conditions, the reward pathway is kept in check by the dopamine transporter, which brings back excess dopamine inside the cell. Scientists believe that cocaine produces its addictive effects by blocking these dopamine transmitters, leading to a buildup of dopamine that is responsible for the intense feelings of pleasure and euphoria. Although the reward pathway is an attractive drug target, prevention of abuse is still preferable to treating an already formed addiction. Even if treatment is successful, almost of half of cocaine users will relapse within two and a half months. As a result, identifying risk factors for drug abuse is a critical area of research that will set the stage for strategies to prevent addiction. Outside of the reward pathway, cocaine has been shown to induce changes in the brain’s plasticity. One form of plasticity is neurogenesis (the creation of neurons), which occurs in the hippocampus even during adulthood. What is important to realize is that adult neurogenesis is an elaborate biological pathway in which neural stem cells proliferate to produce neuroblasts, which then migrate and differentiate into newborn neurons. Moreover, the newborn cells have to survive long enough to be able to integrate into preexisting circuitries. Studies have shown that administration of cocaine to rats decreases cellular proliferation in the hippocampus, whereas cocaine’s effect on long-term survival is still unclear. Regardless, these studies at least show that cocaine addiction and decreased neurogenesis appear to be correlated, suggesting a possible role of neurogenesis in the development of cocaine abuse. To investigate the causal role of neurogenesis in drug addiction, one study reduced hippocampal neurogenesis by exposing rats to radiation. The study found that inhibition of adult neurogenesis increased cocaine-seeking behavior and likelihood of relapse. These findings were the first to show that the manipulation of neurogenesis could be an effective strategy in preventing drug abuse behavior. More specifically, increasing neurogenesis could perhaps prevent cocaine addiction. So far, no published study has examined this possibility. Given that there are mice genetically engineered to have more neurogenesis than normal, we can easily test the hypothesis that increasing neurogenesis may prevent cocaine abuse. Why might a decrease in neurogenesis contribute to addiction behavior? Cocaine can rewire the brain through a variety of pathways, and a decrease in neurogenesis could represent changes in neural plasticity that reinforces addiction behavior. Some reports have shown that cocaine can cause neuronal loss, and thus increasing neurogenesis can boost the body’s endogenous regenerative mechanism to compensate for damaged circuits. Additionally, it is known that stress can also reduce neurogenesis. Given that depressed individuals are more vulnerable to drug addiction, decreased neurogenesis might simply be a reflection of stress that puts individuals at risk for drug abuse. Regardless of my interest in neurogenesis, I don’t think that focusing only on neurogenesis will solve the drug addiction problem, given the multitude of other brain processes involved. I envision that a future treatment might be a combination of both social counseling and medications that target multiple neuronal underpinnings of drug addiction. However, a better understanding of how neurogenesis contributes to drug abuse may lead us toward a greater insight into how neurogenesis participates in brain function.


Gender flexibility is possible in rat brains

Scientists have known for a while that male and female brains in many mammals differ in both form and function, but how they become that way is still a mystery. However, a new study published in Nature Neuroscience sheds some light on how gender may be determined in the brain.


White House pushes back against cyberterrorism

You’re working on your laptop as usual one morning, perusing your favorite social network, when your computer requests a system update. Although nothing seems out of the ordinary, one of those language pack updates you normally barely pay attention to is carrying a not-so-ordinary payload. In the blink of an eye, your system is wrenched from your control, and a complete hard-drive wipe commences, destroying all of your most important work and personal files. An ominous red skeleton appears on your screen with a host of demands. Before you know it, all of your personal files will be shared publicly on the world wide web. This modern-day horror story may seem distant, but company-wide attacks like this occurred just last December, targeting businesses like Sony Pictures Entertainment. These attacks against American individuals and companies have not gone without response. American intelligence agencies traced the attack’s trail across the globe as it bounced from compromised computer to compromised computer until it eventually led to its source — North Korea. The question, however, isn’t how to find cyber criminals, but what to do once they are caught. In the case of the Sony attacks, any actions taken become a sensitive diplomatic move. On Jan. 2, U.S. President Barack Obama issued an executive order instructing several government agencies to take action against the Democratic People’s Republic of Korea (DPRK). The Treasury Department, for example, froze any assets controlled by the American financial system of individual officials, the DPRK and its supporters. On April 1, Obama signed a new, more powerful executive order. This new executive order has no geographic limits and expands possible sanctions to any foreign attackers and their supporters. “Cyber threats pose one of the most serious economic and national security challenges to the United States, and my administration is pursuing a comprehensive strategy to confront them,” Obama said in his press conference. “As we have seen in recent months, these threats can emanate from a range of sources and target our critical infrastructure, our companies and our citizens.” The U.S. government is now authorized to freeze the assets of any identified perpetrators. Michael Daniel, the White House cybersecurity coordinator, wrote on the White House Blog, “Our focus will be on the most significant cyber threats we face — namely, on actors whose malicious activities could pose a significant threat to the national security, foreign policy, economic health, or financial stability of the United States.” Daniel listed cyber threats that will be targeted by the government: compromising critical services in American infrastructure; disrupting computer or network availability; misappropriating funds, economic resources, trade secrets or personal information for gain; knowingly receiving said misappropriations, or attempting or assisting in any of these attacks. Daniel believes it is also important to note who the U.S. government is not targeting. “These sanctions will in no way target the victims of cyber attacks, like people whose computers are unwittingly hijacked by botnets or hackers. Nor is this Order designed to prevent or interfere with the cybersecurity research community when they are working with companies to identify vulnerabilities so they can improve their cybersecurity,” Daniel said. Looking forward, we can expect further bolstering of U.S. cyber defenses. From diplomacy engagements to trade policy to law enforcement mechanisms, the government will be taking a more severe stance against cyber and technology threats. Congress legislation is currently under works to enhance and modernize the American cybersecurity approach. Thus, while we have been introduced to a new, modern-day horror story, we are also introduced to a new, modern-day hero. As Obama announced upon signing this new executive order: “Starting today, we’re giving notice to those who pose significant threats to our security or economy by damaging our critical infrastructure, disrupting or hijacking our computer networks or stealing the trade secrets of American companies or the personal information of American citizens for profit.”


Few weight-loss programs are effective, study finds

Over two-thirds of the adults in America are considered overweight or obese, and nearly two-thirds of those have reported trying to lose that weight. This desire for weight loss fuels a $2.5 billion per year industry, but new research at the Johns Hopkins School of Medicine suggests that many commercial programs may not even be very effective.


Polio virus successfully shrinks brain tumor

Injecting someone with a virus in order to cure brain cancer may sound surprising, but it also may be the cancer treatment of the future. Although still at the beginning of their research, scientists at Duke University have successfully used the polio virus to treat brain tumors. Each year, eight out of every 100,000 persons in the United States are diagnosed with primary malignant brain tumors, representing about two percent of all cancers diagnosed. Primary brain tumors localize in the brain and rarely travel to other parts of the body. Brain tumors that are considered “malignant” are life-threatening and invade the normal brain tissue that surrounds it, growing rapidly. Malignant brain tumors may also spread to the spine. Brain tumors are caused by an abnormal change in the cells’ genes. In most cases the cause is unknown and could have resulted from a complex set of circumstances. This change in the structure of the genetic material is thought to result from inherited genes, environmental factors or even just a random mutation. Gliomas are specific types of tumors that occur within the brain and are the most commonly diagnosed brain tumors. These tumors are thought to arise from glial tissue, which has the role of supporting and nourishing the brain tissue. They are graded I (most optimistic outlook) to IV (most malignant) based on their microscopic appearance. The grade is indicative of their malignancy; growth rate, blood supply, presence of a necrotic center, invasive potential and similarity to normal cells are taken into account. Glioblastomas are grade IV tumors that are highly aggressive, growing rapidly and spreading quickly to other parts of the brain. Early symptoms depend upon the region of the brain that the tumor invades. Sometimes glioblastomas are discovered only when a brain scan is done for some other unrelated reason. These tumors are difficult to treat because they are composed of different types of cells that may or may not respond to certain types of therapies. Also, the tumors commonly contain finger-like projections, which make surgical removal particularly challenging. Once diagnosed, brain tumors can be treated by several methods. Tumors may be removed during an open skull surgical procedure called a craniotomy; however, if the tumor is located in an inaccessible location or near critical structures, a surgical procedure may cause damage to other areas of the brain. Stereotactic radiosurgery is a technique using Cobalt-60 radiation to damage the tumor cells to the extent that they are unable to reproduce and perform their cellular activity. Radiotherapy uses multiple treatments of radiation from linear accelerator machines. Chemotherapy employs pharmaceutical medicines to kill abnormal cells. However, many are plagued with toxic side effects so sometimes the treatment regime consists of a combination of methods. Recently, a new, radical treatment method for brain tumors has been introduced by the Preston Robert Tisch Brain Tumor Center. The idea of employing viruses to attack cancer tumors has existed for over 100 years. However, only recent advances in the application of genetic engineering to these viruses have made the practical use of this technology a reality. Dr. Matthias Gromeier is a molecular biologist at Duke University and has been working on the application of viruses to treat cancer tumors for 25 years. He has developed a method to slightly alter the virus by removing the part of its genetic material that makes it harmful to normal cells. Then, the virus can only make more copies of itself using the only other cells around — the cancer cells. During this process, it kills the cancer cells and leaves the normal surrounding cells unharmed. These “oncolytic viruses” are therefore altered so they only infect and kill cancer cells. Stephanie Lipscomb, a 23-year-old nursing student from South Carolina, was the first patient to receive a successful oncolytic virus treatment for her brain tumor. Lipscomb was diagnosed with a stage IV glioblastoma when she was 20 years old, and doctors predicted she would only have two years left to live. She underwent surgery, chemotherapy and radiation therapy. The tumor reoccurred each time. In 2012, Lipscomb underwent an experimental treatment at Duke University Medical Center. Doctors there injected a genetically modified polio virus directly into her brain tumor. The entire procedure took over six hours. The tumor began to shrink, disappeared and has not returned to date. There is no sign of a tumor in Lipscomb’s brain now, and the word “cured” is being used by some of her doctors. While this new treatment modality is promising, researchers at Duke caution that much more work is needed before it can become routine. For Stephanie Lipscomb, however, it is a lifesaver.


Facebook use may be linked to depression

At some point, you’ve probably logged on to Facebook to check a quick fact and instead found yourself spending an hour mechanically scrolling through their News Feed. If you’ve felt frustrated that everyone else seems to be having a blast while you’re squinting at an electronic screen, you’re not alone. A recent University of Houston study revealed that the amount of time people spend on Facebook is correlated with symptoms of depression. The study attributed this depression to the social comparisons that Facebook users engage in. Regardless of whether people reported engaging in upward social comparison — contrasting their lives with people whom they consider more popular — or downward social comparison — contrasting with those below them in social standing — they still displayed more depressive symptoms. According to the authors of the study, comparing one’s self to others on Facebook can be more emotionally damaging than in-person social comparisons, because people tend to only post the best aspects of their lives on Facebook. Sophomore Amanda Jan, a member of A Place to Talk (APTT), could not definitively conclude that Facebook is causing depression, but said that other factors are also responsible for feelings of depression among students. “I think it’s really difficult to say because this is the first generation that’s ever had a Facebook,” Jan said. “Obviously, there’s a huge usage of Facebook on our campus and in our generation in general. But I think that either way, whether it’s caused by Facebook or not, the important thing is there is a tremendous need among our generation... for support with mental health.” This was not the first study to tie Facebook to negative emotions. A study conducted by the University of Missouri in February found that Facebook users tend to feel unhappy and envious when they comb through their friends’ pages without liking or commenting on others’ posts. A 2013 study also revealed that Facebook makes its users feel more alienated, and it determined that the users it surveyed had similar personality traits. This outcome could not be explained by arguing that lonely people are more likely to visit Facebook. Another study linked negative body image to time spent on Facebook. After surveying adolescent girls about their use of the site, researchers found that girls who spent a lot of time looking at others’ photos on Facebook tended to be unhappy with their weight. However, the researchers acknowledged that girls who are self-conscious about their appearance may be more likely to view pictures on Facebook than girls who are not. On the other hand, not all research agrees that Facebook is making us sadder. In July of 2009, several researchers found that the amount of Facebook use is correlated with an increase in its users’ social trust, political involvement and life satisfaction. An additional study took a more quantitative approach to linking Facebook with happiness. After analyzing hundreds of millions of posts, it found that a positive Facebook post causes the number of negative posts subsequently made by one’s friends to fall by a factor of two. A negative Facebook post, however, prompts the amount of friends’ positive posts to fall by only a factor of 1.3. This suggests that positive emotions are better transferred through Facebook posts than negative ones. Jan thinks the effect that Facebook has on users’ emotions varies based on their personality, their mood and the particular posts they are looking at. She referred to the blast of statuses on college admissions as one Facebook activity that feels intimidating, but at the same time notes how Facebook can make her more politically informed. “I’m not the kind of person who tends to go out and read articles on my own, but if [my friends] put up articles, I have a tendency to click on them and read them. Whatever way [Facebook’s effect] leans tends to be based on who you are as a person, and how you’re feeling that day, before you even get on Facebook,” Jan said. Jan explained how she would react if a student approaches her and describes symptoms of depression. “One of the things we’re taught in APTT is when someone walks into the room... you don’t know anything about their history or anything if they don’t tell it to you. I wouldn’t first of all assume that Facebook is either correlated to or causing this student to be upset,” she said. “If it does seem to be related to Facebook, I would hope that whoever they talk to can flush it out a little more and then ask how they think they should go about things in the future if Facebook is being a negative impact on their life.”


JohnCon unites gaming, fiction enthusiasts

This past weekend marked the 19th annual JohnCon, a 48-hour convention held every year on the Homewood Campus that caters to gamers and board game enthusiasts. This year’s convention was packed with Pokémon tournaments, diverse panelists and gaming of all sorts. “[The convention] serves as a place for Hopkins students and people in the community to hang out... sharing their interest for games and fiction,” junior Emily Forster, vice president of JohnCon, said. The convention was hosted by the University’s Science Fiction and Fantasy Association, Anime Club and Pen & Paper Gaming Club. JohnCon is marketed as a fun and convenient way for Hopkins students to relax and learn about the world of fiction. In addition to gaming, it offers a place for vendors to sell their figurines and game cards. The convention is free, but donations are encouraged to support future JohnCons. The first event of the convention, laser tag, took place outside the Glass Pavilion. Because the turnout was small, three-man teams participated in each round. Though some competitors seemed shy at first, they loosened up after running around in the sun and barrel-rolling in the grass, trying to stay alive for as long as possible. Besides the laser tag games, which occurred on each day of the convention, there were various panels that took place in either the Sherwood Room of Levering Hall or the Arellano Theater. Topics ranged from fan fiction tips to comedy shows by +2 Comedy. +2 Comedy is a group of stand-up comedians well-versed in the world of fiction. Mentions of Star Wars and Lord of the Rings abounded, and even though some of the audience may not have been familiar with references to other franchises such as Dungeons and Dragons, the relaxed and inclusive atmosphere encouraged everyone to participate in the act. Some jokes were painfully awkward, with chuckles from the audience breaking the silence, while others, mostly about movies, were more well-received. A major portion of the show targeted the Hobbit films, with the comedians and celebrity guest Dan Barnett, also known as Epic Dan, taking turns cracking jokes at the long, disappointing series. As the show approached its end, +2 Comedy sprung a surprise, offering a chance for an audience member to receive a DVD and syphilis (or rather, a plush doll of the bacteria). To get a chance at the prize, participating audience members had to risk something of their own. The comedians accepted offers as diverse as lint from a wallet to a $20 bill, but they ended up selecting the person who offered up a plaid jacket. After a brutal ten-minute quiz, during which he had to guess movie titles from their Netflix descriptions, the plaid-jacket owner took home a recording of +2 Comedy shows and the plush doll. Compared to Sherwood and the Arellano Theater, the atmosphere of the Glass Pavilion was charged with intense card and video game competition. Throughout the weekend, the room hosted tournaments for Magic the Gathering, Pokémon, Super Smash Bros, and more. While some participants were very competitive, others joined in just to have fun with their friends. The tabletop game, Warhammer 40k, was one of the more fierce events and spanned two days. The game relies on dice rolls to determine movement, attacks and saves. Prizes were handed to the winners of the tournaments, driving players to play their hardest and backstab their friends. The last portion of the convention featured a raffle and appearances by guests such as Danny Birt, composer, college instructor and award-winning author of Between a Roc and a Hard Place. Birt read some of his works to the audience and performed music pieces inspired by science fiction. During multimedia hour, Birt also played videogames with the audience, allowing fans to interact with the accomplished writer. For those who wanted more time with guests, JohnCon offered a raffle in which an attendee won the chance to eat dinner with comedians from +2 Comedy as well as other invitees. Junior Jerry Fang commented on JohnCon’s slow start. “[I was] disappointed since there weren’t a lot of people there on the first day of the convention,” Fang said. Forster, vice president of JohnCon, praised the event’s inclusivity. “Students from Hopkins, the community around Hopkins and even people from MICA can hang out and share their interests in gaming and fiction,” she said.


Study finds unpasteurized milk is dangerous

Raw milk, the natural and unprocessed form of milk, has grown in popularity many think it tastes better and is healthier than regular milk. However, new research from the Johns Hopkins Center for a Livable Future suggests that raw milk might actually be harmful. The study was conducted in response to a bill presented to the Maryland House of Delegates during the 2014 session of the General Assembly, which aimed to loosen regulations regarding the sale of raw milk in Maryland. Currently, all sales of raw milk are prohibited in Maryland, and the bill called for allowing on-farm sale. According to the Maryland House of Delegates website, a formal decision on the bill has not yet been passed. Keeve Nachman, director of the Food Production Program and a professor at the Bloomberg School of Public Health (JHSPH), led the study along with his team from the Center for a Livable Future, including Benjamin Davis and Cissy Li. Nachman previously worked for the Environmental Protection Agency and the Army Corps of Engineers after receiving his Ph.D. at JHSPH. His current work revolves around human health risks associated with the drugs used in food animals. The team’s method included reviewing over 1,000 journal articles published on the subject and analyzing some of them to determine the health risks and benefits of raw milk. They concluded that drinking raw milk carries an increased risk of foodborne illness as compared to drinking pasteurized milk, but that the reason why has not yet been identified. The researchers stated that any benefits that could come from drinking raw milk do not outweigh the definite health risks. Raw milk not gone through the pasteurization process in which milk is heated in order to kill bacteria that could have contaminated it during milking or transportation. Proponents of raw milk believe that it tastes better and is significantly healthier because it contains natural proteins and bacteria, which reduce allergies and lactose intolerance. However, opponents fear it could risk public health and safety. Some who experience lactose intolerance claim that the raw milk lessens the symptoms of the condition, but a study done at Stanford University concluded that raw milk does not decrease symptoms. Raw milk contains just as much lactose as properly pasteurized milk. According to the FDA, the bacteria that can be found in unpasteurized milk include salmonella, campylobacter, listeria, and Escherichia coli. Infections of this type can lead to vomiting, diarrhea, abdominal pain, fever, headache and in some serious cases, even death. Young children, pregnant women and the elderly are particularly at risk. The Farm-to-Consumer Defense Fund states, though, that consumers should have the right to access the foods they want. Nachman’s research did find that raw milk increased the risk of illness to nearly 100 times greater than pasteurized milk. This correlates with other studies from the FDA that found that over half of milk-related illness was caused by raw milk, even though only around 3.5 percent of the population drinks it. Nachman’s research did not however find any solid evidence supporting the claims that raw milk is healthier. Most people understand the risks of drinking unpasteurized milk, and that the consequences can even be deadly. However, the benefits are less understood. Nachman believes that they would have to be investigated further. Forty-two states currently allow the sale of raw milk to varying degrees, but Maryland is among states including Montana, Nevada, Iowa, Louisiana, West Virginia, Delaware, New Jersey and Hawaii where it is completely banned. Nachman concludes that from a public health perspective, it is safer right now to discourage the sale of raw milk. He also suggests in the study that people should be more aware of the potential risks of consuming raw milk, especially the risks to vulnerable members of the population such as pregnant women, children and the elderly. For many the question is not as much about the actual health benefits and risks of raw milk, but about the freedom to decide for one’s self. Does the government have the right to restrict an individual’s right to choose their milk source, or does it have the obligation to protect that individual from danger? These are not easy questions to answer, and more research is certainly needed, but the decision will left to the Maryland House of Delegates.


The Brain Wave: Scientists unravel the brain’s synaptic anatomy

Communication between different neurons provides the functional basis for how the nervous system works. For example, neurons in the retina relay visual information to higher-order neurons in the cortex to derive our conscious perception of the external world. As a result, understanding which neurons talk to each other is fundamentally necessary for gaining insight into the biological basis of brain function. One way to understand how neurons connect with each other is through tracing their connectivity patterns. Each neuron sends its axon, a wire-like protrusion, to a nearby or far-away neuron. Electrical ripples known as action potentials travel through the axon to reach the axon terminal, triggering release of chemicals called neurotransmitters. These neurotransmitters will bind to receptors on the adjacent neuron’s dendrites. The functional contact between each neuron is a synapse. As a result, tracing where these axons go can provide a clue to which populations of neurons communicate with each other, and ultimately, a better understanding of the brain’s anatomical wiring diagram. For a long time, tracing was done via injecting a dye that moves throughout neuronal processes. These reagents could either travel backward (retrograde) or forward (anterograde). By following where the dye ends up, it is possible to figure out which region the injected neuron is projecting to, or which neuronal population is sending information to the injected neuron. However, these classical dye tracers suffer from a major drawback. They do not prove the existence of synapses, since localization of the dye at an area does not necessarily imply the presence of synaptic connections. As a result, scientists needed a type of tracer that could not only traverse through axons but also jump across synapses. To that end, rabies viruses have been utilized as tracers due to their ability to infect a large number of neurons via synapse jumping. In addition to providing proof that synapses exist between neurons of interest, another benefit to the rabies virus is that it can be used to map longer pathways that involve more than two distinct populations of neurons. However, the results can be extremely difficult to interpret, since it is difficult to control the number of synapses that the virus crosses. As a result, tracing experiments that utilize rabies viruses must have clearly delineated timelines so that the chronological order by which synapses were crossed can be determined. Recent developments in genetics combined with viral technologies have made vast improvements to rabies virus tracing. By swapping out the comments necessary for infection and transsynaptic spread, the modified version of rabies virus can now only jump one synapse. The new technique is also much more precise because the virus can now infect only neurons that express the necessary molecular components, whereas before, the virus could infect any cell in its vicinity. Termed transsynaptic viral tracing, this technology was first used to trace the brain’s olfactory pathways. The importance of tracing methodologies cannot be overemphasized. The brain is a biological entity composed of interconnected neuronal populations. As a result, the first step toward understanding the circuit mechanism of brain function is to obtain a map of the wiring diagram. This could later lead to developments of brain diseases in which neuronal circuits are perturbed.



Astronaut embarks on longest space mission

In August of 1996, U.S. Navy Captain Scott J. Kelly reported to the Johnson Space Center for astronaut training. Nineteen years of service to NASA, three spaceflights and 180 days in the International Space Station (ISS) later, Kelly, 51, begins his most ambitious endeavor yet — a mission to spend an entire year in space. This past Friday, Kelly launched aboard a Soyuz rocket, accompanied by cosmonauts Mikhail Kornienko and Gennady Padalka. Kelly is scheduled to return in March 2016 by which time he will have spent more than 500 days in Earth’s orbit. Unlike his cosmonaut colleagues, however, Kelly will provide NASA with a unique opportunity to monitor the effects of a harsh space environment on the human body by bringing his biological twin U.S. Navy Captain Mark E. Kelly into the equation. Mark retired from service in the U.S. Navy and NASA in 2011. Thus, in a near-perfect case study of the “nature vs. nurture” argument, Scott will orbit the Earth, enduring the effects of extended time in space, while Mark remains on solid ground below. This mission holds more significance than satiating mere scientific curiosity. Data collected through observation of the Kelly twins will contribute to the future of space travel as NASA and other space agencies attempt increasingly longer space voyages. In a few decades, this mission may even serve as the bedrock to NASA’s potential missions to Mars. “All of those things really affect the bodies of astronauts,” Julie A. Robinson, NASA’s chief scientist for the space station, said during a news conference in January. “They push them to something not at all unlike aging on Earth, where their balance is disrupted, their hearts are weaker, their immune system isn’t functioning as well, their muscles are weaker and their bones are being lost.” Scott Kelly’s scientific contribution won’t be without its personal drawbacks. While Kelly looks forward to the space station, he also dislikes the confinement. Kelly said that he’ll miss his friends and family, being able to get away from work and going outside. Ultimately, Scott Kelly’s mission is a potent reminder of both what magic lies ahead of us and behind us as we take to the stars.


Minimally invasive surgery lowers healthcare costs

As healthcare costs continue to rise, the U.S. continues to search for ways to provide affordable coverage to all citizens. The Affordable Care Act, Medicare and Medicaid are modern players in the long fight against increasing healthcare costs. However, a new quantitative study may soon change the way we think of hospital costs. The healthcare industry in the U.S., made up of physicians, hospitals and insurance providers, represents a $3.8 trillion dollar industry, according to Forbes. Yet, a McKinsey Study showed that the United States, while spending more on healthcare per capita than any other developed country, does not enjoy higher health outcome measures such as percent obesity and life expectancy. Many theories exist regarding this paradox: the higher cost of medical procedures, an overly bureaucratic administration, increased length of inpatient stay and even a lack of preventative medicine. However, whatever the reason may be, it is clear that a systematic cost reduction is critically needed. Minimally invasive surgery has flourished in the current age of technology-based medicine. Through innovations in biomedical engineering, physicians can perform what were once open surgeries with minimally invasive tools such as laparoscopic devices and robotically controlled instruments. The Mayo Clinic reports that because patients often have just a very small incision, there is lesser chance of painful and life-threatening postoperative infections. Recovery times also increase because less healthy tissue is damaged during the procedure. Surgical procedures represent a substantial single contributor to aggregate healthcare expenses. A new study led a professor of surgery at the Hopkins School of Medicine, Marty Makary, and published in The Journal of the American Medical Association (JAMA) Surgery, took a quantitative approach to surgical costs by studying the cost savings and number of postoperative complications avoided by performing minimally invasive surgery versus open surgery. Makary said in the report that minimally invasive surgery is an often-overlooked opportunity to make surgery safer and less costly. For their study, the researchers used the 2010 National Inpatient Sample for patients undergoing an appendectomy (the removal of the appendix), a partial colectomy (removal of part of the colon) or a lung lobectomy (removal of part of the lung). In order to limit the effect of confounding variables, Makary removed instances of emergency surgery and high-risk patients. From this dataset, Markary and his team were able to observe open and minimally invasive surgeries (MIS) with and without postoperative complications. In order to study the cost of postoperative complications associated with open surgery, the researchers considered seven postoperative complications listed in the Agency for Healthcare Research and Quality’s Patient Safety Indicators. The team first built a two-stage regression model for excess cost in cases with and without postoperative complications. From their model, Markary was able to create two simulations in which patients with open surgery instead underwent minimally invasive surgery and from there compute the cost savings, number of complications avoided and number of hospital days avoided. In the first simulation, hospitals that were performing a low number of MIS (i.e., up to the 83rd percentile of hospitals) performed as many MIS as the 83rd percentile. In the second scenario, all hospitals increased their number MIS by 50 percent from the baseline. The investigators found that there was a marked decrease in surgical costs, postoperative complications and hospital stays in both simulations. If hospitals increased their rate of MIS to that of the 83rd percentile, patients could have 169,819 fewer days in the hospital and 4,306 fewer postoperative complications. In total, this would mean a $377 million reduction in annual cost. As Makary concludes, the team’s results indicate that MIS is underutilized and should be a choice given to patients more often. While not applicable in all cases, lower cost, less harmful minimally invasive surgeries may be an effective solution to reducing the fiscal burden of healthcare while also improving patient satisfaction.



Psoriasis medication reduces patches better

Characterized by painful red patches on the skin covered with thick silvery scales, psoriasis is a chronic autoimmune skin condition that afflicts roughly 125 million people worldwide. Newly released data from a clinical study shows that Cosentyx, a psoriasis treatment manufactured by Novartis, is 21 percent more effective than the widely administered treatment Stelara.



The Brain Wave: Immune cells lower neuron growth in seizures

Seizures are almost like firestorms in the brain, causing neurons to fire uncontrollably and resulting in aberrant motor behavior and the loss of consciousness. Despite their seriousness, we still have no good way to treat them. However, a recent study by Taito Matsuda and colleagues from Japan has uncovered a novel pathway between hippocampal neurogenesis and the immune system, potentially providing a new treatment avenue for epilepsy.


Stars make sounds too high for us to hear

Just as the elusive dog whistle is beyond our mere human auditory capabilities, there is an entire reality out there full of waves beyond our visual spectrum, patterns beyond our recognition and dimensions beyond our reach.


After Ebola, Africa faces possible measles outbreak

It may seem as though danger from the Ebola epidemic is gone, but new research from the Bloomberg School of Public Health (JHSPH) suggests otherwise. The study, led by Justin Lessler and released in the March 13 issue of Science, found that disruptions to the West African health care, caused by the Ebola crisis, have led to a significant decrease in vaccinations and a consequent increase in susceptibility to a variety of other diseases.


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