Humans are some of the most cooperative species on the planet, but is it a learned behavior or one we’re genetically disposed to?
Click here to read the full article on Scienceline
Tag: biology
Recreating a Home for Gut Parasites is Really Hard
Heidi Elmendorf, a biologist at Georgetown University, studies the parasite giardia, and to do so has to re-create our gut environment in the lab.
Click here to read the full article on Motherboard
A Chemical Cocktail for Love
Love has been compared to drugs so many times, so I won’t invent a new analogy (though I do think Beyonce does it best with her single “Drunk in Love”). There is, however, some truth to this oft-used allusion: Scientists have found that there is a predictable biochemical reaction to falling in love with someone. With the Valentine’s Day season approaching, it seemed only fitting to write about it.
It all starts with the neurotransmitter dopamine. A neurotransmitter is a chemical produced in our brains — depending on where it’s present in the brain, it may have different effects. You’ve probably heard of this chemical before; it’s actually quite well known for the role it plays in addictions. Though dopamine has a number of important functions in bodies, the one involved in love — and other addictions — is called the mesolimbic pathway. This particular pathway is the reward pathway; when you bite into a delicious piece of cake or win at a slot machine, dopamine surges through your brain. The same thing happens when you first fall in love or experience lust — whatever you want to call it.
Dopamine is powerful stuff. A few years ago, biological anthropologist Dr. Helen Fisher scanned several individuals’ brains while they were looking at pictures of their sweethearts. She found that of the many different regions of the brain that lit up, one of them was the same region that becomes activated by a cocaine rush.
But without norepinephrine, dopamine is useless.
Norepinephrine is another neurotransmitter; it provides us with focus, attention and directs the general euphoria provided by dopamine. Dopamine could have you in a cheerful mood, but when you see that special someone at a party and he or she immediately takes all your attention, that’s norepinephrine at work. In an interview on Radiolab, science reporter Neely Tucker from The Washington Post equated this neurotransmitter to physical passion and infatuation: It’s the drive that makes us literally want to cross that one person off your to-do list.
So while this is, in fact, the neurotransmitter that makes your eyes dilate and your pulse increase, if you’re like me it also means your palms get sweaty and you lose the ability to form complete, coherent sentences.
But have no fear! If you’re able to make it through those first awkward conversations to those first few dates (or however you get close to your significant other), there’s a chance the rushes of dopamine and norepinephrine will wear off into something more permanent: oxytocin.
Oxytocin is the attachment hormone, and in terms of romantic love, oxytocin is the difference between a fling and a long-term relationship. After you spend a lot of time with a partner, the spark becomes less exciting. And not because your significant other is boring; your relationship just isn’t new anymore. Some couples are dependent on the dopamine and norepinephrine to keep them going; when there’s no more left, they go their separate ways and look to start the chemical trip all over again. And that’s fine — assuming you can find someone else who pleases you, you’re in for another great high.
But for others, depleting levels of these first two neurotransmitters leads to the creation of a relationship that generates oxytocin. Oxytocin doesn’t have the same highs, but it provides the feeling of contentment and companionship associated with life partners. It’s a much more emotionally stable feeling, and it can come anywhere between six months and a year after seeing someone.
What we call love requires all three of these chemicals, though; one is not better than the others in any biological sense. I suppose it’s not very romantic to think of love as just another set of chemical reactions. It implies that when you swoon when your significant other remembered your favorite flowers or took you on a picnic or to that concert you’ve always wanted, it was all just some chemicals at play.
But there are two ways of making this fact hopeful: First, it takes some of the pressure off to find “the one.” Who knows how many people will trigger those chemicals for you? Second, it helps put breakups into context: We’re just going through a little withdrawal, but ultimately we’re going to be okay.
Happy Valentine’s Day. May your Feb. 14 be filled with all the neurotransmitters you deserve, and then some.
Originally printed in The Hoya
Mosaicism: A Genetic Puzzle
We may not actually be who we think we are. Or at least, we may be a little more complicated than we give ourselves credit for.
That’s what the genetic study of DNA has begun to explore. The study of genetics looks at our DNA, which is our supposedly unique combination of genes that makes us unquestionably unique. For years, scientists assumed that we each had one genome. That concept seems pretty logical to most people.
Except, biology can be dubious. As scientists become more familiar with human genetics, it seems that a single genome may not be all there is to make us who we are. Many scientists are beginning to recognize that within our bodies, there may actually be a variety of genomes. Welcome to the world of chimerism, also known as mosaicism, which encompasses the concept slightly more humanely.
When the Human Genome Project began in 1990, scientists were only concerned with taking one sample of DNA from consenting adults. Back then, DNA sampling was hugely expensive but was used to find an easier way of identifying personalized medicine. What originally was a government endeavor quickly became commercialized to private companies like 23andme that offered patients a quick genome mapping to track ancestors, explore preventative medicine and have a better understanding of who they are as humans.
This would be great progress if we had only one genome. But it’s looking like that’s not the case.
Once, a mother who gave birth to her sons was told that she and her sons weren’t a genetic match. This was hugely disturbing, obviously, but doctors discovered that she, like a few others in the world, had two forms of DNA in her body. Additionally, a British woman stumped doctors when she donated both Type A and Type O blood. (We typically have only one type.) Turns out, she had accidentally absorbed her twin’s blood while still in the womb. But these were written off as exceptions, not the rule.
This condition became known as chimerism, named after the combination of lion, snake and goat from Greek mythology. In recent biotech history, scientists have been able to fabricate different chimeras in rather controversial experiments: There have been pigs able to live with human blood, goat-sheep hybrids (geeps) and human cells fused with rabbit eggs. While the purposeful engineering of chimeras strikes a negative chord with animal rights activists, it is scientifically possible.
And if we’ve been able to engineer it, it’s fairly logical that it occurs naturally. In 2012, University of Washington scientists examined 59 female brains post-mortem. They expected to find only female genetic information, but were shocked to see that neurons in 63 percent of them had Y chromosomes, which distinguish males from females. A study by the International Journal of Cancer found that male genes can be found in female breast tissue as well. Some forms of leukemia have been linked to mutation in blood cells where bits of DNA are moved from one chromosome to another.
The widespread rates found in both healthy and unhealthy individuals imply that the majority of us probably have different genomes within. This shows that the human genome — really “a” human genome — is anything but a complete database of genetic identity. What used to be groundbreaking science has proven to be just the tip of the iceberg. If we really want to use genome projects for personalized medicine, we’re going to have to find a shrewd way to get around this unexpected surprise. Typically, the science that gets the most publicity — and therefore funding — is more headline-worthy than genomes. But if these developments show us anything, it is that biologists absolutely must do more exploring and they need the financial support to do it.
I don’t know much about my own genetic history; I’ve never needed to. But I like the idea ofmosaicism. It makes humanity seem even more like art.
Originally published on The Hoya.
Finding Fulfillment in Biology
Sometimes, Jesuits are even ahead of the scientific community.
Two years ago on Sept. 16, Fr. Kevin O’Brien, S.J., wrote a piece for The Hoya called “Using the Three D’s to Guide a Modern Life.” In it, he describes depth, distraction and discernment: three things necessary to understanding’s life’s meaning. O’Brien calls on students to strive to live deeply without distraction and to allow room for discernment for those that do. In other words, he calls on us to live with meaning for the greater glory of God.
When I first read his words, they made intuitive sense; of course we should try to live fully and for others. It appeals to our morals. And while intuition may be enough for some of us, it is certainly gratifying when biology backs us up.
Professors at the University of North Carolina and the University of California, Los Angeles recently examined the white blood cells of 80 healthy volunteers and had the same volunteers fill out an online survey about their happiness.
These researchers decided to compare different types of happiness to gene expression. They found that depending on the type of happiness each person reported, they expressed different genetic traits. Those whose happiness was predominately based on buying new things — what we might call hedonic happiness — had more biological markers in their white blood cell DNA known to lead to more inflammatory immune responses.
On the other hand, those who reported finding happiness by serving others had lower levels of these inflammatory genetic markers. In a nutshell, this study indicates that the more we strive for a deeper, activity-based happiness, the healthier our gene expression gets.
Of course the issue of correlation versus causation blurs our conclusions. The National Academy of Science officially summarized the study by saying that those who live to serve others are significantly less stressed. And, given the negative side effects of living constantly under stress, I’d translate that to the surprising truth that living deeply for others actually makes us healthier.
Granted, it’s hard to pin down the exact relationship here, and perhaps there’s no relationship and we just found a fluke trend. And of course, there are those who will derive happiness from both buying the new iPhone and volunteering at D.C. Reads. Biology can be a fickle thing.
But there’s a part of me — my unscientific gut reaction — that believes that maybe there’s a difference in our physical bodies when we feel directed toward a higher purpose.
Think about it: If we’re not always consumed with the material costs of living, it’s easier to dismiss temporal misfortunes. As much as the little things in life add up — the money we have, the number of Facebook posts on our walls or the grades we get — our relationships ultimately matter more.
At the end of the day, it’s easier for me to forgive myself for a poorly written philosophy paper when I remember that my work to foster meaningful relationships has been more successful. When I get into a fight with those who matter most to me, however, it’s much harder to excuse myself. A paper is has a temporary impact; these other things are more permanent.
It seems to me that whether or not we identify with religion, we can all benefit from taking O’Brien’s words to heart. If we live striving to do the work that matters — the kind that benefits others, forms lasting connections and is unmotivated by monetary distractions — our immune systems will respond favorably. As far as the current scientific literature shows, there’s no downside to trying.
Originally published on The Hoya.
This is What a Thought Looks Like at a Molecular Level
I went hiking this weekend, and I saw a lizard. I was excited because it looked like this was the kind of creature that could regrow its tail as a defense mechanism. I thought about regrowing limbs, I thought about the heat from the sun, and I thought about how happy I am to be human and not a lizard with a blue tail.
Typically, we think without thinking about it. In fact, many find it hard not to think. That’s why meditation requires serious practice. But, for something that takes place so quickly and routinely, there are a lot of intermediate steps we don’t even have time to consider.
Thought, as it turns out, is not instantaneous (even though it feels like it when you decide that yes, you will have another chocolate), as Carl Zimmer explores. In fact, most signals in the body function analogously to wires or other electronics. Even though listening and comprehending your friend’s story over the phone feels immediate, it actually takes a fraction of a second for his or her voice to travel across the airwaves.
Believe it or not, the invention of the telegraph in 1844 inspired our first model of how nerves work. When it took a split second for messages to be transferred across the country, it seemed to be just as simultaneous as thoughts or feelings perceived in different regions of the body. In 1850, German scientist Hermann von Helmholtz used frog legs and wires to measure the time it took the electric signal to travel through the dead animal. It turned out to be roughly a tenth of a second. Additionally, Helmholtz tested to see how long it took people to feel different shocks on different parts of the body. Though it took longer to feel discomforts on the extremities than on the base of the back, he found that it also took about a tenth of second.
This discovery led the earliest neuroscientists to believe that nerves send signals to the brain, and that our brains analyze them further. These signals, called neurotransmitters, are received by the ends of axons. If the neurotransmitters are like baseballs, axons function kind of like mitts. Axons communicate with neurons to tell them how to interpret these different signals.
Complicating the story, of course, is the fact that regions of neurons our brains process different things. For example, the part of our brain that processes sight is called the thalamus, which then sends another signal back to the visual cortex in the back of the brain. So in reality, these signals may bounce around several different parts of the brain before we really form a complete thought about what they mean.
This means that different processes come at different speeds. Sound is processed almost immediately — hearing a loud noise will trigger an instinctual response in just .05 seconds.Sight happens relatively quickly too. However, our brains purposefully slow down some receptors so that our consciousness doesn’t go into sensory overload.
Taking a big step back, our thoughts and decisions come down to a lot of different molecules (and a slight current that comes with a varying charge gradient). These changes can be traced down more or less to chemical reactions. And, if you consider the basic structure of our nerves, we’re not that much more than chemistry with a little electric current.
The technical aspects of neuroscience interest me greatly, but the philosophical implications of these processes compel me more. If it turns out that our thoughts and musings come down to a few signals here or there, what does that mean about some of the more profound human experiences? What about love? What about grief? What about poetry, and the inexplicable beauty of a small lizard in the middle of the woods on a hot summer day?
I like to think I — my essential “Katherine-ness” — is more than just some grey matter influenced by different compounds. But at the end of the day, there’s something rather comforting in the idea that all the overwhelming experiences and thoughts we have just come down to a few simple chemical reactions and interaction.
Originally published on Policy Mic.
Can Fingernails Help Us Regenerate Lost Body Parts?
n the spirit of superheroes featured in some of this summer’s blockbuster films (I’m looking at you, Clark Kent!), I started thinking about why we’re actually not superhuman ourselves. Don’t get me wrong: We humans can do some amazing things. But one area where some of our least advanced neighbors beat us is the field of regeneration.
Unless you’re Wolverine, regeneration is something that has been left to starfish, zebrafish, and certain types of lizards. Rather than forming scar tissue where the limb was taken off, these animals are able to generate entirely new appendages complete with skeletal, muscular, and nervous support. Biologists refer to this process as epimorphic regeneration, which means that these animals convert previously undifferentiated cells into specific types of cells. These cells are called blastema, and most animals aren’t lucky enough to produce them.
Humans can’t quite regrow entire feet or hands, but it turns out that we’ve got the roots of the capability to do so in our fingernails, of all places.
In 2010, a California native named Deepa Kulkarni successfully regenerated her pinky tip after she lost it to an unfortunate door slam. Doctors used a powder made from ground up pigs’ bladder to act as a sort of scaffolding to attract stem cells from bone marrow, rather than forming scar tissue. Believe it or not, the biomedical company ACell has already begun manufacturing this product called MatriStem.
However, just as important as the MatriStem is the tiny bit of fingernail that remained on Kulkarni’s wound: NYU scientist Dr. Mayumi Ito researched the situation further, and discovered that fingernails contain a family of proteins that promote cell growth called Wnts (pronounced “wints”) that are also found in mice. The MatriStem acted as a base to help these proteins function, but the Wnts found in the nail did the actual heavy duty building.
In theory, Wnts help normal cells function like blastema, and we’d just need an extra trigger to get the body to produce these proteins in areas other than fingernails. So far, genetic manipulation experiments have been successful in mice, where subjects have regrown bone, nervous tissue and muscles where there haven’t been any natural stem cells present before. If this technique could be perfected, it would have huge implications for amputees.
Right now, over 60% of lower limb amputations result from diabetes. Other common reasons people must have appendages usually result from trauma or infection. However, if biologists perfect Wnt technology, amputations and any remaining disabilities could become a thing of the past.
Of course, any sci-fi-sounding solution has its equally terrifying complications: right now, lizards that regrow their limbs aren’t able to regrow the exact same limb. Rather, they grow something that functions similarly, but is either shorter or longer. While it’s frightening to think of the implications of a regrown limb gone wrong, the fact that we could potentially regain functionality — like our reptilian friends — is incredible.
Original article published on Policy Mic.
Can Avatars Make Us Immortal? This Multimillionaire Says It Could Happen
Dmitry Itskov is perfectly sane.
The Russian multimillionaire and former media magnate appears to be like any other 32-year-old man — even rather reserved by most standards — but with a rather unique hobby. Itskov pursues immortality through the development of avatars which carry the entire contents of the human brain. He calls it the 2045 Initiative.
Basically, Itskov dreams of continuing conscious life outside the biological sphere in the form of a relatively inexpensive non-biological carrier. Despite the fact that this goal aligns with some of the most popular sci-fi hits (think Avatar), this Itskov has some heavy-weight supporters in the scientific community, including scientists from Harvard, M.I.T, and Berkeley. Later this month, roughly 30 of the scientists who see at least some rationale in Itskov’s pursue will speak at the second annual 2045 Global Future Conference in Manhattan. This conference, much like the ones featured in the Iron Man movies, are more of a technological showcase than actual conference. Tickets go for $750 a piece.
Most of these researchers are not looking to upload our brains contents to computers through a complicated theory of the “quantum nature of consciousness” by Sir Roger Penrose, but the idea of artificial intelligence replacing biological forms sparks questions about the nature of life itself.
Itskov truly believes this project harbors altruistic measures. These avatars would not feature some of what we refer to as disabilities or limitations; there would be no congenital heart defects or missing limbs. He believes that avatars will ultimately reduce world hunger (machines only need maintenance) and that charities will eventually be structured to provide inexpensive avatars to the poor. It’s a nice dream, really; one filled with longevity.
But is that what we really want?
Do we define life as mere consciousness? Most biologists would argue that we would not. Additionally, what does this mean about our relationship with technology? While many casually exaggerate that they are ‘addicted’ to their smart phones, in the case of avatars or robots, we would literally depend on machines to keep our thoughts and conscious presence meaningful.
In my opinion, a key part of our time on earth are the things we feel and the relationships we cultivate. It’s about wiggling our toes in the grass and enjoying the sun on our skin. It’s about building our families, learning new ideas, and experiencing culture that can’t quite captured through a camera lens. It’s about the faith we feel, or don’t, and about forcing ourselves to live in the present because we never know when we’ll have that moment again.
Either way, the rapid pace at which technology develops and the financial resources available mean that this idea could potentially become a reality for the mega-rich in the next 50 years or so. Itskov now spends most of his time traveling to meet new scientists who may be able to help him with his mission, and speaking to the public about what he views as his solution to the end of suffering. When he is not traveling, he meditates and claims to live like a monk.
What do you think? Would avatars be the best way to eliminate future pain and continue the human race? Or is this idea too much of a real-life science fiction blockbuster?
Original article available on Policy Mic.
Katherine Ellen Foley 