Most people are familiar with the idea that people who are blind have better hearing than those with normal vision. It was formerly thought that this compensation for lack of vision could only develop in the brains of the very young. However, new research conducted at the University of Maryland and Johns Hopkins University suggests that the brain may be more flexible than previously believed.
In the study, researchers kept one group of healthy mice in total darkness for a week, and exposed the other group to natural light for a week. Then the team used electrodes to measure activity in neurons in the mice’s primary auditory cortex. This is the part of the brain that processes how loud a sound is and its source. By analyzing this data, researchers found that the mice who were exposed to a week of darkness had much better hearing than the control mice.
This suggests that the circuits that process sensory information can be re-wired in the brains of adult mice, even after the early critical period for hearing. These findings seem to contradict the idea that once the critical period for hearing is past, the auditory system doesn’t respond to changes in an individual’s soundscape.
Pregnancy is…? This sentence can end in a multitude of ways depending on whose answering the question. If I ask the ‘teen-mom-too-good-to-be-true-seventeen year-old-boyfriend’ who isn’t worried about nothing, then he’d probably say…well I would’ve asked but he just stormed off in his 92′ Bronco. You know, the one with the flames on the side? If I ask the nervous husband who has been day dreaming of becoming that perfect family man ever since he got into the relationship, then he’d probably say: If it’s a girl, I will be the dragon that protects my princess’ castle. If I ask the soon-to-be-BIG-brother whose busy doing doughnuts in his fisher price corvette yelling “look mom, no hands,” he’d probably say: This doesn’t change the cookie rations, does it? And finally if I ask the pregnant mother-to-be
if she thinks she’s gained weight what she’s praying for, she’d probably say: Just not your father’s personality, PLEASE, not your father’s personality.
Pregnancy is engaging. It brings together families, can tear relationships apart, and creates changes in the daily routine. Most notable is women’s change in body size. Bodily size and the awareness of that size can create multiple obstacles. Typically, pregnant women are thought to be inhibited in their ability to adapt to these obstacles, however, pregnant women are just as capable as non-pregnant individuals. Today, we’ll discuss their ability to asses depth perception and whether or not they can fit through openings such as doorways. Thanks to perceptual-motor-recalibration, pregnant women are just as good at adjusting their spatial awareness of their environment to match their constantly changing bodies.
Schizophrenia is a mental disorder often presented in patients by abnormal thought processes, impaired emotional responses, and negative symptoms. As a chronic disorder that affects ~1% of all people, schizophrenia can be have debilitating effects on patients, especially on their social lives. Due to the lack of knowledge on its pathophysiology and also the heterogeneity of the symptoms, it has been increasingly important to understand the genetics of schizophrenia.
Due to the marked reduction in fecundity seen in schizophrenic patients, the high heritability of the disorder pointed to the possibility that genetic alleles that were risk factors might occur as de novo mutations. Previous exome sequencing studies showed no promising results, but the inconclusive results were likely due to small sample size and a narrow focus on target genes. Two recent studies, the largest of their kind, gathered data from nearly 7000 people (nearly 3500 patients) from Sweden and Bulgaria, and showed that genetic effects on schizophrenia seemed to be very complex. Specifically, both papers published in Nature reflected on the implication of genetic mutations in clusters of specific proteins that governed signaling networks dealing with learning and memory. The studies identified the presence of de novo mutations, often nonsense mutations, notably in genes related to the PSD (post-synaptic density of dendrites), the calcium channels, the postsynaptic ARC complex, and the NMDA receptors.
If you have ever noticed that men tend to forget things quite often, especially compared to women, you are not alone. A research team led by Professor Jostein Holmen in Norway conducted a large, longitudinal population health study called Hunt3 to reach the conclusion that men are more forgetful than women, regardless of their age. This is one of the largest health studies ever performed, with answers from over 48,000 people leading to their conclusions.
The participants were asked at the beginning of the study if they had problems remembering things, if they had problems remembering dates and names, if they had a memory of what they did one year ago, and if they could remember details about specific conversations.
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.
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.
Google, IBM, Microsoft, Baidu, NEC and others use deep learning and neural networks in development of their most recent speech recognition and image analysis systems. Neural networks have countless other uses, so naturally there are tons of startups trying to use neural networks in new ways. The problem being faced with now, is how exactly to implement neural network models in a way that mimics the circuitry of the brain. Brains are highly parallel and extremely efficient; the ultimate achievement of a neural network model would be able to perform large scale parallel operations while being energy efficient. Current technology is not well suited for large-scale parallel processing, and it is nowhere near as efficient as our brain, which uses only 20 watts of power on average (a typical supercomputer uses somewhere along the order of several megawatts of electricity).
One way in which future computers could mimic the efficiency of the brain is being developed by IBM. IBM believes that energy efficiency is what will guide the next generation of computers, not raw processing power. Current silicon chips have been doubling in power through Moore’s Law for almost half a century, but are now reaching a physical limit. To break through this limit, researchers at IBM’s Zurich lab headed by Dr. Patrick Ruch and Dr. Bruno Michel want to mimic biology’s allometric scaling for new “bionic” computing. Allometric scaling is when an animal’s metabolic power increases with its body size; the approach taken by IBM is to start with 3D computing architecture, with processors stacked and memory in between. In order to keep everything running without overheating, this biologically-inspired computer would be powered, and cooled, by so-called electronic blood. Hopefully this fluid will be able to multi-task, and like blood supplies sugar while taking away heat, accomplish liquid fueling and cooling at the same time.
Huntington’s disease, a neuro-degenerative disorder, affects roughly 5-10 out of every 100,000 people. The disease acts by deteriorating many structures in the brain, beginning with the Caudate Nucleus, which is involved in motor control. By the end of their lives, patients are expected to lose about 30% of their brain mass.
In the last few decades much has been learned about the disease: we now know that it’s genetic, caused by a mutation on the 4th chromosome, and leads the ‘so-called’ huntingtin protein to grow too long and fold in on itself incorrectly. Parents with Huntington’s disease each have a 50% chance of passing it on to their child. Symptoms usually appear between 35 and 45 years of age, and the life expectancy after the first appearance of symptoms is 10-20 years. There currently is no treatment for Huntington’s itself, so patients can only receive a little bit of relief from their symptoms while the disease progresses.
So far, there is no real consensus among scientists about how exactly the disease works, but it’s generally agreed that it all starts with the mutated huntingtin protein. What if that protein was somehow changed or blocked? This idea prompted some experimentation by Holly Kordasiewicz and her colleagues.
For those interested in scientific research, the Nobel Prize is an esteemed award, recognizing one’s work and dedication. However, many student researchers are often disillusioned about the kind of work that is put in to receive such high praise. More often than not, these individuals did not suddenly discover something new. To be sure, their findings are the fruits of years of research and passion in the field of science. As a great model of dedication, recent Nobel laureate Thomas Südhof provided incredible insight to our understanding of the human brain communication. But, once again, his work was in the basic-science field, on a topic which, in fact, we learn about in our introductory neuroscience courses. In this brief article, I will outline the most recent findings from Dr. Südhof’s lab in hopes of showing aspiring researchers that continued diligence and passion for learning is most important.
Neurons communicate with each other by a signaling process mediated by what is known as action potentials. Changes in concentration and electrical gradients cause the action potentials to fire down the neuron, until it reaches the synaptic bouton. It is here that one neuron forms a synapse with another neuron. The synapse is the site at which communication is happening. But, for the most part, two neurons are not physically connected, so how does communication happen? In a process called neurotransmission, when the action potential reaches the end of the neuron, an influx of Ca2+ ions cause vesicles to release certain chemicals out of the neuron, as a signal to the next. These vesicles are like little packets of neurotransmitter chemicals. Herein lies the question that Dr. Südhof sought to illuminate: mechanistically, how do these vesicles actually release the chemicals?