We know from everyday life that, at some point, we need to sleep. In fact, extended sleep deprivation can lead to death. Despite the amount of sleep research that has been conducted, none have been able to clearly reason out the essential function of sleep. However, recently, a promising study by Dr. Nedergaard showed that sleep functions in clearing neurotoxic waste from the brain of mice. In effect, without sleep, these toxins would build up and cause problems for the body.
Specifically, the study looked at what is known as the glymphatic system. Because our central nervous system lacks a lymphatic system which is in our peripheral system, the glymphatic clearance pathway is the primary way in which our brain can “clear” the cerebrospinal fluid (CSF) and interstital fluid (ISF) of the brain parenchyma. This clearance includes functions of getting rid of wastes, soluble proteins, and even controlling the volume of fluid. Interestingly, the Nedergaard study showed that this clearance system works faster when mice were asleep–in other words, the exchange rates of CSF and ISF increased during sleep. In addition, they were able to show that surrounding cells in the brain would shrink in size to allow more efficient clearance.
As we grow and discover new artists, we refine the compilation of music in our brains. But do we stop developing taste in music at a certain age? Many researchers believe that by the age of 14 musical preferences are completely developed. Does this mean that your taste in music is set in stone for the rest of your life? Not exactly.
In an article from the New York Times, David Hajdu points out that major music stars such as John Lennon, Paul Simon, and Aretha Franklin, and many other successful artists all turned 14 during the mid-50s, when rock ‘n’ roll was first becoming a major genre. Altough it may just be a strange coincidence, Hajdu believes that this is what influenced them to pursue music as a career “Fourteen is a sort of magic age for the development of musical tastes,” says Daniel J. Levitin, a professor of psychology and the director of the Laboratory for Music Perception, Cognition and Expertise at McGill University. “Pubertal growth hormones make everything we’re experiencing, including music, seem very important. We’re just reaching a point in our cognitive development when we’re developing our own tastes. And musical tastes become a badge of identity.”
Does the gym seem too far away? Do you feel like you don’t have time to exercise? There may be some good news for couch potatoes like ourselves. Studies are showing that watching a sport causes some of the same physiological effects as actually working out . While watching others exercise, heart rate, respiration, skin blood flow, and sweat release all increase as if you were exercising.
Researchers at the University of Western Sydney inserted fine needles into an outer nerve of volunteers who were shown a static image followed by a video of a jogger for 22 minutes. With these needles, the scientists were able to record electrical signals within nerve fibers that innervate blood vessels. These recordings provided measures of the body’s physiological stress response, particularly muscle sympathetic nerve activity.
The study showed that sympathetic nerve activity increased when volunteers watched the jogger. In comparison, observing the static image caused change in activity. The sympathetic nervous system innervates the heart, sweat glands, and blood vessels, and its activity increases during exercise. This study indicates that its activity also increases while watching another person exercise, indicating that there may be some benefit.
A groundbreaking new research study by Susumu Tonegawa’s team at MIT has opened up grounds for debate in the ethics of neuroscience once again. In Tonegawa’s experiment, neuroscientists were able to implant memories into the brains of mice using optogenetics, a technology in which specific cells can be turned on or off by exposure to a certain wavelength of light. The specific memory manipulated in this study was a conditioned fear response in mice to a mild electrical foot shock.
Researchers in Tonegawa’s lab began by engineering mice hippocampal cells to express channelrhodopsin, a protein that activates specific neurons when stimulated by light. Channelrhodopsin was also modified to be produced whenever c-fos, a gene necessary for memory formation, was turned on. On day one, the engineered mice explored Room A without any exposure to foot shock; the mice behaved normally. As the mice explored this room, their memory cells were labeled with channelrhodopsin. On day two, the same mice were placed into Room B, a distinctly different room, where a foot shock was received; the mice exhibited a fear response. While receiving the foot shocks, channelrhodopsin was activated via optogenetics causing the fear response to be encoding not only to Room B, but Room A as well. To test this hypothesis, the mice were brought back to Room A on day three.
Before babies can crawl or walk, they explore the world around them by looking at it. This is a natural and necessary part of infant development, and it sets the stage for future brain growth. By using eye-tracking technology, scientists were able to measure the way infants look at and respond to different social cues. This new research suggests that babies who are reluctant to look into people’s eyes may be showing early signs of autism.
The researchers at Marcus Autism Center, Children’s Healthcare of Atlanta and Emory University School of Medicine followed babies from birth until age 3, and discovered that infants later diagnosed with autism showed declining attention to the eyes of other people, from the age of 2 months onwards.
It’s just about that time of year again – in just over a week’s time we’ll be sitting down to a huge feast consisting of turkey, stuffing, and mashed potatoes; we’ll be watching the Macy’s Parade soon to be followed by two football games; and we’ll be giving thanks for our reunion with our grandparents, uncles, aunts, cousins, brothers, sisters, parents, and more. Thanksgiving definitely holds a special place in my heart – however, up until recently, it always used to provide just a little bit of stress. That is because, at least in my family, somewhere between polishing off the last roll and preparing for pecan pie one relative or another always asks me, “so what are you studying in school again?” And when I answer “Neuroscience!” I typically get one of two responses: the confused look, followed by “Neuroscience? What is neuroscience?” (typically from the older crowd in the room), or the rolling of the eyes, followed by “What are you going to do with a degree in neuroscience?” (typically from the former engineers and business majors). I love neuroscience, and I know I’ve found my passion studying it here at BU, but those questions always seem to bring with them a certain pressure that I always felt I cracked beneath. However, I recently discovered the perfect way to address both of these questions, and I’m here to let you in on the secret so you can impress your relatives at the thanksgiving dinner table as well. This year, when Grandma or Uncle Tony ask me “why neuroscience?” my answer will be simple – because neuroscience is changing, and will continue to change, the world and how we approach it.
I can already imagine the taken aback look crossing my relative’s faces, and the comment that I’m perhaps being a little dramatic – neuroscience is changing the world? Not only will my answer definitely get their attention, but I’m confident that my answer is correct, and proving my point to my disbelieving family will only make Thanksgiving that much more fun. Neuroscience is the science of understanding the nervous system (that is the system that essentially allows for all of our functioning) on a basic scientific level, and then applying that knowledge to do a bunch of things, from eradicating the diseases that plague the system (Alzheimer’s, Parkinson’s), to applying the knowledge in the classroom so that students of all ages can learn to their full potential. If you take a step back and view the whole picture, it’s not surprising that neuroscience will change the world in our lifetime; as opposed to some other fields, neuroscience is constantly acquiring completely new information about systems that not too long ago used to be a complete mystery – this knowledge is overflowing and already being applied to the real world to make beneficial changes. I will quickly outline two fascinating new outlets of neuroscience that are changing the world right before our very eyes, so that you have solid proof to further widen the eyes of your relatives this holiday season.
As we approach the loved holiday season, we also approach the dreaded weight gain that comes along with it. It probably won’t come as a surprise to you that our brain, specifically the hippocampus, plays a role in resisting immediate or delayed temptation.
The hippocampus deals with memory, including recalling past events and imagining them in the future. A study called “A Critical Role for the Hippocampus in the Valuation of Imagined Outcomes” examines healthy people as well as people with Alzheimer’s disease, which impairs memory and is associated with atrophy of the hippocampus. The study looked at “time- dependent” choices having to do with money in addition to “episodic” choices having to do with food, sports, and cultural events.
Most of us have heard about them but only a few appreciate the power of them. It was more than 20 years ago that scientists discovered the fascinating mirror neurons. It was at the University of Parma, Italy where the first glimpse of mirror neurons occurred. The study’s focus was actually to examine motor neurons involved in hand and mouth actions in macaque monkeys. The basic procedure of the experiment involved monkeys reaching for food while researchers recorded firing in particular neurons. What these researchers found was that some neurons actually fired even when the monkey was not moving but was just watching someone else perform an action. So, one may easily deduce that mirror neurons are neurons that fire both when an animal performs an action and when an animal observes someone else perform an action. Nearly 20 years after the initial macaque monkey experiment mirror neurons studies are still generating fascinating results. The reason for this fascination is that mirror neurons are at the base of extremely important functions such as socialization, empathy and teaching.
More recent discoveries have shown that mirror neurons are critical in the interpretation of both facial expressions and body language. Moreover mirror neurons enable us to understand, empathize and socialize with others. As studies have shown, autistic individuals have trouble understanding other people´s intentions and feelings. Autistic individuals cannot understand the intentions of others while observing their actions. This is believed, at least in part, because autistic individuals have a malfunctioning mirror neuron system. This malfunctioning system disables these individuals’ ability to even try and comprehend someone else’s actions based on observation. In contrast to autistic individuals, people with well functioning mirror neuron system have no problem understanding other people’s intentions, which makes mirror neurons so important.
Before reading this post, I want you to take a look at the website of Bryan Lewis Saunders, specifically the portion that describes his escapade through drugs and self-image. It can be found at http://www.bryanlewissaunders.org/drugs/.
As a brief summary, Saunders took one drug a day for several weeks straight, and drew a self-portrait during the experience of each. Eventually, he changed to more sporadic use due to exhaustion and brain damage issues, but he did continue for quite a while. Saunders ranges the gamut from commonly known drugs such as Adderal, bath salts, and cocaine to more obscure Risperdol and Klonopin. The approach was clearly unscientific, it does delve into some interesting questions concerning our self-image, at least once you go past the initial, “this guy is crazy” response. Although I certainly won’t delve into all of them, I think it’s important to sometimes take a moment and ask them.
First of all, it’s interesting to see how much our self-perception can be altered by something so seemingly trivial as a drug. We consider our image to be an integral part of us, yet it is easily changed. For those who study neuroscience, this is probably unsurprising, as we know that drugs change the chemistry of our body and brain, and are thus likely to alter self-image. However, the extent is quite amazing, if Saunder’s pseudo-experiment is any indication.
Imagine for a second feeling “overcomplete.” You have all of your limbs, and they are perfectly healthy. Yet, you feel as though your leg doesn’t belong to you. It shouldn’t be there, and you know it needs to go. The only way you can feel “whole” again is through its removal. You might be wondering why anyone would want to get rid of a perfectly healthy limb. Well, this phenomenon is the result of apotemnophilia, or Body Integrity Identity Disorder (BIID), a condition characterized “by the intense and long-standing desire for the amputation of a specific limb.” Most know exactly where they want the line of amputation to be, and this place stays fairly constant as time passes. Since it is rare for a surgeon to agree to amputate a healthy limb, many suffering from this condition will unfortunately resort to attempting the amputation themselves. In the past, this rare disorder was thought to be only psychological, and that perhaps the yearning for amputation was simply a way of seeking attention. However, in recent years, studies have shown otherwise.
One study performed by David Brang, Paul D. McGeoch and Vilayanur S. Ramachandran suggests that apotemnophilia is indeed a neurological disorder. The otherwise healthy subjects of the study went through a series of blind skin conductance response tests where they were pinpricked above and below the line where the amputation was. The responses to the pinpricking below the line were much greater than those above it. The resulting differences found suggest some abnormalities with the somatosensory input to the body part in question.
They suspect the disorder to be a consequence of damage to the right parietal lobe, which is responsible for processing sensory input from certain areas and forming our sense of body image. It could be the dysfunction within the right parietal lobe, specifically the right superior parietal lobe, causing irregular sympathetic output. The discrepancy between the signals and body image can lead to the feeling that a certain limb doesn’t belong and should be removed in order to feel “complete.” In addition, most patients have dealt with these feelings since childhood suggesting that the dysfunction is congenital.