Have you ever searched for a ringing phone, feeling your anxiety increase with each ring? Or experienced a mini heart attack when you thought you lost your phone only to discover it was in a different pocket? Most older generations would criticize you for being so obsessed with technology, but recent studies have shown that ‘iPhone separation anxiety’ is a real disorder – and it is plaguing the younger generations of today’s society.
The average person spends about two hours and fifty-seven minutes on a smartphone or tablet every day. Most of us get stressed out if we misplace our phone, are constantly checking for notifications, and even feel ‘phantom vibrations’ – a sensation that we have received a notification when we really have not. Most people would dismiss this anxiety as an unhealthy obsession with technology, but research has shown that these feelings are legitimate and smartphone separation can have serious psychological and physiological effects.
Scientists have known about rhodopsins that are responsible for sensing light for a while. What if there was a way to insert those rhodopsins inside neurons? That’s exactly what scientists were experimenting with in the early 2000s and it’s this idea that lead to the birth of optogenetics. By taking the DNA of channel rhodopsins from algae and inserting them into the membrane of neurons, scientists were able to make neurons sensitive to particular wavelengths of light. Channel rhodopsin and halorhodopsin are among the opins inserted into neurons by injecting viruses. Channel rhodopsin activates neurons while halorhodopsin silences them. Once the neuron expresses the light-gated cation channel channelrhodopsin-2 in its cells membrane, shining light on it for as little as a few milliseconds has a profound effect. It causes the opening of the channelrohodopsin-2 molecules, allowing positively charged ions to enter cell and cause the cell to fire.
Check out this video to see how optogenetics works.
Many experiments today use optogenetics to selectively turn neurons on and off in mice. What makes this method mind blowing is the high spatial and temporal resolution it gives scientists when working with the brain. It can be used on neurons in on a petri dish or within a living animal. It could be used to learn more about the function of particular brain regions. For instance, one could temporarily inactivate one region to observe how it impacts activity in other connected brain regions.
Furthermore, it’s minimally invasive: once the virus containing the rhodopsin has been injected, all the scientist needs to do is shine a pulse of light. Researchers at Stanford have used optogenetics to induce muscle contractions in mice. At Case Western Reserve University, researchers implemented it to restore motor function in rats paralyzed by spinal cord injuries. Could optogenetics be used to recover vision loss, something most humans deal with as they age? Experiments conducted on mice with a lack of photoreceptors shows that shining light on bipolar cells (containing channelrhodopsin-2) causes action potentials to fire in the visual cortex. It would be amazing if scientists could overcome biomedical and technical obstacles to make this work in humans too.
Across the river at MIT, members of the Tonegawa lab have taken the technique of optogenetics one step further. Steve Ramirez and Xu Liu have been working to localize memories in the brain and activate them with a light “switch”. And they have accomplished this feat in mice. Promising experiments with mice suggest optogenetics can be used to turn off traumatizing memories and activate pleasant once. This could have implications for PTSD, where horrific memories could be suppressed. They also have experimented with the idea of implanting false memories into the brain, which they call “Project Inception.” For more information on this work (and a good laugh), check out Steve Ramirez and Xu Liu’s TED talk.
Seems to me like optogenetics is a promising technique that can lead to breakthroughs in neuroscience.
 “The Birth of Optogenetics” http://www.the-scientist.com/?articles.view/articleNo/30756/title/The-Birth-of-Optogenetics/
 “Potential Benefits of Optogenetics” http://optogenetics.weebly.com/what-is-it1.html
Huntington’s disease (HD) is a neurodegenerative disorder that slowly diminishes one’s ability to walk, talk, and reason until eventually control is completely lost. HD is an autosomal dominant genetic disorder, so everyone who carries the gene is guaranteed to develop the disease and will have a 50% chance of passing it on. Currently, there is no cure for this devastating disease, and most die within 10-20 years after onset.
With no treatment or way to stop the progression of HD, the outlook of those diagnosed has seemed pretty bleak. Until now. A new clinical trial for an HD drug is set to enter Phase 1 in 2015. This drug is meant to target the source of HD itself: the Huntington gene.
Neurogenesis occurs in two areas in the human adult: in the dentate gyrus of the hippocampus and in the olfactory system. The hippocampus is vital to learning new information and memory consolidation, thus it makes sense that new neurons need to be born in that region. The olfactory system is needs neurogenesis to process to new information. Majority of neurogenesis actually occurs during prenatal development. In fact humans initially have more neurons that necessary for survival. Apoptosis (programmed cell death) occurs to prune the synapses established during early development.
Many studies have been conducted that investigate ways to increase neurogenesis. Such activities include voluntary physical exercise or being in enriched environments. Experiments with rats have shown that being in an enriched environment where rats are exposed to complex objects, toys, running wheels, etc. spark improvements in performance of tasks measuring levels of learning and memory. For humans, I suppose an enriched environment could be a place involving novel stimuli or
If you think about it, how could neurogenesis be bad? I mean people with neurodegenerative diseases suffer from the consequences of neuronal loss, right? However, according to a study published in May 2014 in Science, exercise could induce amnesia. An article regarding this study states, “Adult mice that exercised on a running wheel after experiencing an event were more likely than their inactive mates to forget the experience.” Thus it appears that the neurogenesis that occurs during exercise may be “wiping out” neurons that encoded previous memories. Furthermore, when neurogenesis was pharmacologically inhibited scientists observed a recall failure in the rats. This article relates this phenomenon to the fact that children cannot form long term memories until they are 3-4 years of age.
Despite controversy about neurogenesis, olfactory ensheathing cells (OECs) have been used to help a paralyzed man walk once again. An article published in October in BBC News describes how doctors in Poland accomplished this feat. The first step to this process was to extract cells from the patient’s olfactory bulbs (they removed one olfactory bulb and grew the cells in culture). Two weeks later the cells were implanted in the areas surrounding the spinal cord damage the patient had experienced. This action allowed the spinal cord cells to regenerate because the nerve grafts acted “as a bridge to cross the severed cord.” The implications of this type of surgery are pretty amazing – it could work wonders for paralyzed veterans/other individuals and people dealing with dysfunctions relevant to spinal cord damage.
Exercise Can Erase Memories – The Scientist
- Srijesa K.
With the diagnosis of ADHD in children on the rise, there is a push for researching a treatment and possible solution as well. There have been numerous studies done on a correlation between increased physical activity and a higher degree of paying attention in those children with ADHD. So, is exercise the treatment that we are looking for?
In a study in the Journal of Abnormal Child Psychology, children in an elementary school classroom setting were randomly assigned to either a physical activity (PA) group or a sedentary classroom (SC) group for 31 minute periods per day for 12 weeks. Parents and teachers were asked to rate ADHD symptoms such as inattention, hyperactivity/ impulsivity, oppositional behavior and moodiness before and after the study was completed. The first analyses of this study found that the PA group was more effective at reducing inattention and moodiness at home. Follow up analyses found that the PA intervention reduced impairment associated with ADHD both at home and at school. An unexpected finding that the SC intervention was potentially useful for managing these ADHD symptoms was also found in this experiment. This study was done with a liberal analysis and without a control group, so that is important to note as well.
Many homeless men have suffered a traumatic brain injury in their life, according to a recent study conducted by researchers at St. Michael’s Hospital.
After collecting data from over 100 men aged 27 to 81 from a shelter in downtown Toronto, researchers found that nearly half of the homeless men surveyed had suffered a traumatic brain injury. Of those who had suffered a traumatic brain injury, 87 percent experienced the injury prior to becoming homeless.
According to new research, positron emission tomography (PET), a functional brain imaging technique, is a promising tool for determining which brain damaged individuals in vegetative states have the potential to recover consciousness. This is the first time researchers have tested the accuracy of functional brain imaging for diagnosis in clinical practice.
The researchers from the University of Liége in Belgium suggest that PET imaging can reveal cognitive processes that would otherwise be hidden to traditional testing. Using imaging in addition to standard behavioral assessments could improve patients with the potential for long-term recovery.
I think I’m funny. Some people say I’m funny. But when the moment presents itself where its my time to shine, all lights on me, this ‘one’ is going to be a knee slapper…nope, not so much. The first time I realized I wasn’t funny was in the eleventh grade in my calculus class. My teacher’s name was Mr. Butke and he easily is ranked in my top 3 ‘all-time’ of the math professors I’ve encountered in my lifetime. He had a mustache that covered his mouth and you never knew whether he was smiling, smirking, or grimacing at you. It kept you guessing, I liked that. He also presented stories of how he slayed cobras in Kenyan villages while pursuing a multi-purpose cure for malaria, encephalitis’ of sorts, and maybe AIDS. Bottom line, he was memorable and his stage presence resonated with my classmates and I.
Numbers. Those arithmetical values that allow us to analyze and measure our surroundings. Without them, our understanding of the world we live in would be far less interesting. But what may be even more interesting is the way we process those numbers and how closely related that process is to spatial reasoning. The connection between space and numbers, specifically how we materialize values in our heads through mental number lines has been studied over the years, revealing that spatial orientation is incredibly important to this hypothetical number line. One study led by cognitive neuroscientist Stanislas Dehaene investigated how number magnitude is spatially organized in our minds and introduced the phenomenon of Spatial-Numerical Association of Response Codes, or the SNARC effect for short.
For years, the brain of a child with autism has been a mystery. Doctors and parents wondered about the cause of autism, and it seemed that they would never get those answers. Autism is characterized on a spectrum with various expressions of difficulty with social interaction including difficulty with verbal and nonverbal communication. Children with ASD (Autism Spectrum Disorder, the official title of ‘autism’ after the May 2013 publication of the DSM-5) are associated with difficulties with motor coordination, attention, intellectual disabilities, and physical health problems like sleep and gastrointestinal problems. Autism is usually presented by age three and the process of diagnosing autism continues to change, according to the Autism Speaks foundation.
Dr. Thomas R. Insel, director of NIMH at the NIH says that “while autism is generally considered a developmental brain disorder, research has not identified a consistent or causative lesion.” The newest reports show that the architecture of the autistic brain is “speckled with patches of abnormal neurons.” In the study published in the New England Journal of Medicine, there is evidence that the brain irregularities of children with autism are due to abnormal prenatal development.