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Mars Base

Scientists discover previously unknown cleaning system in brain - 0 views

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medical

shared by Mars Base on 16 Aug 12 - No Cached
  • A previously unrecognized system that drains waste from the brain at a rapid clip has been discovered by neuroscientists at the University of Rochester Medical Center
  • highly organized system acts like a series of pipes that piggyback on the brain's blood vessels, sort of a shadow plumbing system that seems to serve much the same function in the brain as the lymph system does in the rest of the body – to drain away waste products
  • hopeful that these findings have implications for many conditions that involve the brain, such as traumatic brain injury, Alzheimer's disease, stroke, and Parkinson's disease
  • ...11 more annotations...
  • made the findings in mice, whose brains are remarkably similar to the human brain
  • Scientists have known that cerebrospinal fluid or CSF plays an important role cleansing brain tissue, carrying away waste products and carrying nutrients to brain tissue through a process known as diffusion
  • The newly discovered system circulates CSF to every corner of the brain much more efficiently, through what scientists call bulk flow or convection
  • It's as if the brain has two garbage haulers – a slow one that we've known about, and a fast one that we've just met
  • How has this system eluded the notice of scientists up to now
  • the system operates only when it's intact and operating in the living brain, making it very difficult to study
  • study the living, whole brain, the team used a technology known as two-photon microscopy, which allows scientists to look at the flow of blood, CSF and other substances in the brain of a living animal
  • If the glymphatic system fails to cleanse the brain as it is meant to, either as a consequence of normal aging, or in response to brain injury, waste may begin to accumulate in the brain. This may be what is happening with amyloid deposits in Alzheimer's disease
  • Perhaps increasing the activity of the glymphatic system might help prevent amyloid deposition from building up or could offer a new way to clean out buildups of the material in established Alzheimer's disease
  • took an in-depth look at amyloid beta
  • found that more than half the amyloid removed from the brain of a mouse under normal conditions is removed via the glymphatic system
Mars Base

New drug could treat Alzheimer's, multiple sclerosis and brain injury - 0 views

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Alzheimer MultipleSclerosis GrabBag

shared by Mars Base on 25 Jul 12 - No Cached
  • A new class of drug
  • shows early promise of being a one-size-fits-all therapy for Alzheimer's disease, Parkinson's disease, multiple sclerosis and traumatic brain injury by reducing inflammation in the brain
  • The drugs
  • ...22 more annotations...
  • target a particular type of brain inflammation
  • brain inflammation, also called neuroinflammation, is increasingly believed to play a major role in the progressive damage characteristic of these chronic diseases and brain injuries.
  • offers an entirely different therapeutic approach to Alzheimer's than current ones being tested to prevent the development of beta amyloid plaques in the brain
  • The plaques are an indicator of the disease but not a proven cause
  • given to a mouse genetically engineered to develop Alzheimer's, it prevents the development of the full-blown disease
  • identifies the optimal therapeutic time window for administering the drug, which is taken orally and easily crosses the blood-brain barrier.
  • In previous animal studies, the same drug reduced the neurological damage caused by closed-head traumatic brain injury and inhibited the development of a multiple sclerosis-like disease. In these diseases as well as in Alzheimer's, the studies show the therapy time window is critical
  • work by preventing the damaging overproduction of brain proteins called proinflammatory cytokines
  • Scientists now believe overproduction of these proteins contributes to the development of many degenerative neurological diseases
  • When too many of the cytokines are produced, the synapses of the brain begin to misfire
  • mouse model of Alzheimer's received MW151 three times a week starting at six months of age, right at the time the proinflammatory cytokines began to rise. This would be the comparable stage when a human patient would begin to experience mild cognitive impairment
  • drug protected against the damage associated with learning and memory impairment
  • before Alzheimer's memory changes are at a late stage may be a promising future approach to therapy
  • In M.S., overproduction of the proinflammatory cytokines damage the central nervous system and the brain
  • proteins directly or indirectly destroy the insulation or coverings of the nerve cells that transmit signals down the spinal cord
  • insulation is stripped, messages aren't properly conducted down the spinal cord
  • When mice that were induced to develop an M.S.-like disease received MW151 orally, they did not develop disease as severe.
  • After a traumatic brain injury, the glia cells in the brain become hyperactive and release a continuous cascade of proinflammatory cytokines
  • As a result of this hyperactivity, researchers believe the brain is more susceptible to serious damage following a second neurological injury.
  • when MW151 is given during an early therapeutic window three to six hours after the injury, it blocks glial activation and prevents the flood of proinflammatory cytokines after a traumatic brain injury
  • early on after traumatic brain injury or a even a stroke, you could possibly prevent the long-term complications of that injury including the risk of seizures, cognitive impairment and, perhaps, mental health issues
  • Stroke also causes inflammation in the brain that may also be linked to long-term complications including epilepsy and cognitive deficits
Mars Base

Wireless signals could transform brain trauma diagnostics - 0 views

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scibyte94 brain

shared by Mars Base on 15 May 13 - No Cached
  • New technology
  • is using wireless signals to provide real-time, non-invasive diagnoses of brain swelling or bleeding.
  • The device analyzes data from low energy, electromagnetic waves, similar to the kind used to transmit radio and mobile signals
  • ...15 more annotations...
  • The technology
  • could potentially become a cost-effective tool for medical diagnostics and to triage injuries in areas where access to medical care, especially medical imaging, is limited
  • The researchers tested a prototype in a small-scale pilot study of healthy adults and brain trauma patients admitted to a military hospital for the Mexican Army
  • The results from the healthy patients were clearly distinguishable from those with brain damage, and data for bleeding was distinct from those for swelling
  • symptoms of serious head injuries and brain damage are not always immediately obvious, and for treatment, time is of the essence.
  • The researchers took advantage of the characteristic changes in tissue composition and structure in brain injuries
  • For brain edemas, swelling results from an increase in fluid in the tissue
  • For brain hematomas, internal bleeding causes the buildup of blood in certain regions of the brain.
  • Because fluid conducts electricity differently than brain tissue, it is possible to measure changes in electromagnetic properties.
  • Computer algorithms interpret the changes to determine the likelihood of injury.
  • The study involved 46 healthy adults, ages 18 to 48, and eight patients with brain damage, ages 27 to 70.
  • engineers fashioned two coils into a helmet-like device, fitted over the heads of the study participants
  • One coil acts as a radio emitter and the other serves as the receiver. Electromagnetic signals are broadcast through the brain from the emitter to the receiver
  • the waves are extremely weak, and are comparable to standing in a room with the radio or television turned on
  • The device's diagnoses for the brain trauma patients in the study matched the results obtained from conventional computerized tomography (CT) scans
Mars Base

Casual marijuana use linked to brain abnormalities in students - 0 views

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scibyte127 marijuana

shared by Mars Base on 19 Apr 14 - No Cached
  • Young adults who used marijuana only recreationally showed significant abnormalities in two key brain regions that are important in emotion and motivation
  • This is the first study to show casual use of marijuana is related to major brain changes
  • the degree of brain abnormalities in these regions is directly related to the number of joints a person smoked per week
  • ...19 more annotations...
  • The more joints a person smoked, the more abnormal the shape, volume and density of the brain regions
  • Some of these people only used marijuana to get high once or twice a week
  • think a little recreational use shouldn't cause a problem
  • data directly says this is not the case
  • Scientists examined the nucleus accumbens and the amygdala—key regions for emotion and motivation, and associated with addiction—in the brains of casual marijuana users and non-users
  • chers analyzed three measures: volume, shape and density of grey matter
  • to obtain a comprehensive view of how each region was affected.
  • Both these regions in recreational pot users were abnormally altered for at least two of these structural measures
  • The degree of those alterations was directly related to how much marijuana the subjects used
  • Through different methods of neuroimaging, scientists examined the brains of young adults
  • ages 18 to 25, from Boston-area colleges; 20 who smoked marijuana and 20 who didn't. Each group had nine males and 11 females
  • The users underwent a psychiatric interview to confirm they were not dependent on marijuana
  • The changes in brain structures indicate the marijuana users' brains are adapting to low-level exposure to marijuana
  • The study results fit with animal studies that show when rats are given tetrahydrocannabinol (THC) their brains rewire and form many new connections. THC is the mind-altering ingredient found in marijuana
  • think when people are in the process of becoming addicted, their brains form these new connections
  • In animals, these new connections indicate the brain is adapting to the unnatural level of reward and stimulation from marijuana. These connections make other natural rewards less satisfying
  • The brain changes suggest that structural changes to the brain are an important early result of casual drug use
  • researchers did not know the THC content of the marijuana, which can range from 5 to 9 percent or even higher
  • The THC content is much higher today than the marijuana during the 1960s and 1970s, which was often about 1 to 3 percent
Mars Base

How Our Brain Balances Old and New Skills - 0 views

www.scienceworldreport.com/...alances-old-and-new-skills.htm

scibyte113 BrainTraining

shared by Mars Base on 12 Dec 13 - No Cached
  • To learn new motor skills, the brain must be plastic: able to rapidly change the strengths of connections between neurons, forming new patterns that accomplish a particular task
  • if the brain were too plastic, previously learned skills would be lost too easily.
  • A new computational model developed by MIT neuroscientists explains how the brain maintains the balance between plasticity and stability
  • ...31 more annotations...
  • and how it can learn very similar tasks without interference between them.
  • The key
  • is that neurons are constantly changing their connections with other neurons
  • not all of the changes are functionally relevant - they simply allow the brain to explore many possible ways to execute a certain skill, such as a new tennis stroke
  • As the brain learns a new motor skill, neurons form circuits that can produce the desired output
  • according to this theory
  • As the brain explores different solutions, neurons can become specialized for specific tasks
  • brain is always trying to find the configurations that balance everything so you can do two tasks, or three tasks, or however many you're learning
  • Perfection is usually not achieved on the first try, so feedback from each effort helps the brain to find better solutions
  • complications arise when the brain is trying to learn many different skills at once
  • Because the same distributed network controls related motor tasks, new modifications to existing patterns can interfere with previously learned skills.
  • particularly tricky when you're learning very similar things
  • such as two different tennis strokes
  • computer chip,
  • instructions for each task would be stored in a different location on the chip.
  • the brain is not organized like a computer chip. Instead, it is massively parallel and highly connected - each neuron connects to, on average, about 10,000 other neurons
  • That connectivity offers an advantage, however, because it allows the brain to test out so many possible solutions to achieve combinations of tasks
  • neurons
  • have a very low signal to noise ratio, meaning that they receive about as much useless information as useful input from their neighbors
  • The constant changes in these connections,
  • researchers call hyperplasticity
  • balanced by another inherent trait of
  • Most models of neural activity don't include noise, but the MIT team says noise is a critical element of the brain's learning ability
  • This model helps to explain how the brain can learn new things without unlearning previously acquired skills
  • the paper shows is that, counterintuitively, if you have neural networks and they have a high level of random noise, that actually helps instead of hindering the stability problem
  • Without noise, the brain's hyperplasticity would overwrite existing memories too easily
  • low plasticity would not allow any new skills to be learned, because the tiny changes in connectivity would be drowned out by all of the inherent noise
  • The constantly changing connections explain why skills can be forgotten unless they are practiced often, especially if they overlap with other routinely performed tasks
  • skills such as riding a bicycle, which is not very similar to other common skills, are retained more easily
  • Once you've learned something, if it doesn't overlap or intersect with other skills, you will forget it but so slowly that it's essentially permanent
  • researchers are now investigating whether this type of model could also explain how the brain forms memories of events, as well as motor skills
Mars Base

Could scientists peek into your dreams? (w/ video) - 0 views

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scibyte89 Dreams

shared by Mars Base on 05 Apr 13 - No Cached
  • small new study suggests
  • Visual experiences you have when dreaming are detectable by the same type of brain activity that occurs when looking at actual images when you're awake
  • The scientists created decoding computer programs based on brain activity measured while wide-awake study participants looked at certain images
  • ...16 more annotations...
  • right after being awakened from the early stages of sleep, the researchers asked the subjects to describe the dream they were having
  • used functional MRI to monitor brain activity of the participants and polysomnography to record the physical changes that occur during sleep
  • compared evidence of brain activity when participants were awake and looking at real images to the brain activity they saw when participants were dreaming
  • the study shows it may be possible to use brain activity patterns to understand something about what a person is dreaming about
  • current approach requires the data of image viewing and sleep within the same [person
  • methods being developed for aligning brain patterns across people
  • there are practical applications to the research
  • evidence suggesting that the pattern of spontaneous brain activity is relevant to health issues
  • researchers chose to awaken the subjects in light sleep rather than in deeper "rapid eye movement" (REM) sleep solely to make the research easier to do
  • it takes at least an hour to reach first REM stage, it would be difficult to get sleep and dream data from multiple participants
  • why it is so hard to remember a dream minutes after waking up
  • thinks it is because particular neurotransmitters or brain regions involved in memory are not active during sleep
  • During sleep and dreaming, part of the brain—the higher visual cortex—is working as if seeing images
  • one expert said the results are intriguing, he was cautious
  • previous disappointments relating brain activity to complex visual experience
  • like to see this replicated
Mars Base

Ultrathin flexible brain implant offers unique look at seizures - 0 views

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scibyte21

shared by Mars Base on 14 Nov 11 - No Cached
  • Researchers funded by the National Institutes of Health have developed a flexible brain implant that could one day be used to treat epileptic seizures
  • a type of electrode array that conforms to the brain's surface – to take an unprecedented look at the brain activity underlying seizures
  • Someday, these flexible arrays could be used to pinpoint where seizures start in the brain and perhaps to shut them down
  • ...11 more annotations...
  • These flexible electrode arrays could significantly expand surgical options for patients with drug-resistant epilepsy
  • In an animal model, the researchers saw spiral waves of brain activity not previously observed during a seizure
  • Similar waves are known to ripple through cardiac muscle during a type of life-threatening heart rhythm called ventricular fibrillation.
  • A stimulating electrode array might one day be designed to suppress seizure activity, working like a pacemaker for the brain
  • The brain contains billions of interconnected neurons that normally transmit electrical pulses
  • During a seizure, these pulses occur in abnormal, synchronized, rapid-fire bursts that can cause convulsions, loss of consciousness and other symptoms
  • is made of a pliable material that is only about one quarter the thickness of a human hair
  • It contains 720 silicon nanomembrane transistors in a multiplexed 360-channel array, which allow for minimal wiring and dense packing of the electrodes
  • The flexibility of the array allows it to conform to the brain's complex shape, even reaching into grooves that are inaccessible to conventional arrays
  • the array could be rolled into a tube and delivered into the brain through a small hole rather than by opening the skull
  • The researchers tested the flexible array on cats. Although mice and rats are used for most neuroscience research, cats have larger brains that are anatomically more like the human brain, with simplified folds and grooves
Mars Base

Just a few years of early musical training benefits the brain later in life - 0 views

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scibyte109

shared by Mars Base on 07 Nov 13 - No Cached
  • Older adults who took music lessons as children but haven't actively played an instrument in decades have a faster brain response to a speech sound than individuals who never played an instrument,
  • As people grow older, they often experience changes in the brain that compromise hearing
  • the brains of older adults show a slower response to fast-changing sounds, which is important for interpreting speec
  • ...10 more annotations...
  • recent studies of musicians suggest lifelong musical training may offset these and other cognitive declines
  • previous studies show such age-related declines are not inevitable
  • the current study,
  • explored whether limited musical training early in life is associated with changes in the way the brain responds to sound decades later
  • t the more years study participants spent playing instruments as youth, the faster their brains responded to a speech sound.
  • For the study, 44 healthy adults, ages 55-76, listened to a synthesized speech syllable ("da") while researchers measured electrical activity in the auditory brainstem
  • This region of the brain processes sound and is a hub for cognitive, sensory, and reward information
  • researchers discovered that, despite none of the study participants having played an instrument in nearly 40 years
  • participants who completed 4-14 years of music training early in life had the fastest response to the speech sound (on the order of a millisecond faster than those without music training).
  • a millisecond faster may not seem like much, but the brain is very sensitive to timing and a millisecond compounded over millions of neurons can make a real difference
Mars Base

New drug reverses loss of brain connections in Alzheimer's disease - 0 views

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scibyte99 Alzheimer

shared by Mars Base on 18 Jun 13 - No Cached
  • The first experimental drug to boost brain synapses lost in Alzheimer's disease
  • combines two FDA-approved medicines to stop the destructive cascade of changes in the brain that destroys the connections between neurons, leading to memory loss and cognitive decline.
  • The decade-long study
  • ...21 more annotations...
  • shows that NitroMemantine can restore synapses, representing the connections between nerve cells (neurons) that have been lost during the progression of Alzheimer's in the brain
  • These findings actually mean that you might be able to intercede not only early but also a bit later
  • Alzheimer's patient may be able to have synaptic connections restored even with plaques and tangles already in his or her brain.
  • study, conducted in animal models as well as brain cells derived from human stem cells,
  • team mapped the pathway that leads to synaptic damage in Alzheimer
  • found that amyloid beta peptides, which were once thought to injure synapses directly
  • actually induce the release of excessive amounts of the neurotransmitter glutamate from brain cells called astrocytes that are located adjacent to the nerve cells.
  • Normal levels of glutamate promote memory and learning, but excessive levels are harmful
  • Alzheimer's disease, excessive glutamate activates extrasynaptic receptors, designated eNMDA receptors
  • which get hyperactivated and in turn lead to synaptic loss
  • lab had previously discovered how a drug called memantine can be targeted to eNMDA receptors to slow the hyperactivity seen in Alzheimer's.
  • memantine's effectiveness has been limited.
  • memantine—a positively charged molecule—is repelled by a similar charge inside diseased neurons
  • memantine gets repelled from its intended eNMDA receptor target on the neuronal surface.
  • FDA approval of memantine in 2003
  • a fragment of the molecule nitroglycerin—a second FDA-approved drug commonly used to treat episodes of chest pain or angina in people with coronary heart disease—could bind to another site that the Lipton group discovered on NMDA receptors.
  • memantine rather selectively binds to eNMDA receptors, it also functions to target nitroglycerin to the receptor
  • by combining the two, Lipton's lab created a new, dual-function drug
  • researchers developed 37 derivatives of the combined drug before they found one that worked
  • By shutting down hyperactive eNMDA receptors on diseased neurons, NitroMemantine restores synapses between those neurons
  • NitroMemantine brings the number of synapses all the way back to normal within a few months of treatment in mouse models of Alzheimer's disease. In fact, the new drug really starts to work within hours
Mars Base

Exceptional Memory Linked To Bulked-up Parts Of Brain - Science News - 0 views

www.sciencenews.org/...ed_to_bulked-up_parts_of_brain

scibyte21

shared by Mars Base on 14 Nov 11 - No Cached
  • some real-life people can remember every day of their lives in detail
  • Those superrememberers have more bulk in certain parts of their brains, possibly explaining the remarkable ability to recall minutiae from decades ago
  • brain region involved in such incredible recall has been implicated in obsessive-compulsive disorder
  • ...11 more annotations...
  • OCD and superior memory might have a common architecture in the brain
  • Scientists have long studied people with memory deficits, but there haven’t been many studies on people with exceptional memories
  • 11 people who scored off the charts for autobiographical memory. These people could effortlessly remember, for instance, what they were doing on November 2, 1989, and could also tell you that it was a Thursday
  • Using brain scans, researchers found that people with supermemories had larger brain regions associated with memory
  • a brain structure called the lentiform nucleus, a cone-shaped mass in the core of the brain, was bigger in people with exceptional memories
  • This brain area has been linked to obsessive-compulsive disorder
  • The subjects haven’t been clinically evaluated for OCD, but LePort says that there are some similarities
  • The ability to organize their memories by dates seems to relieve anxiety
  • These people could encode information more effectively, or have a better system of retrieving it, or both
  • Though no genetic tests have been performed, some of the volunteers have reported that family members share extraordinary powers of recall
  • The volunteers are now keeping detailed diaries, so that the scientists can test whether particular kinds of memories are better suited to recollection. People might be better at remembering emotional memories, for instance
Mars Base

Why Teenagers Are So Impulsive | Science/AAAS | News - 0 views

news.sciencemag.org/...why-teenagers-are-so-impulsive

scibyte110

shared by Mars Base on 16 Nov 13 - No Cached
  • When teenagers successfully resist an urge in a common test of impulsivity, they show increased activation in a brain region associated with restraint
  • suggesting that their brains have to work harder to avoid acting on the impulse
  • Why do teens—especially adolescent males—commit crimes more frequently than adults
  • ...20 more annotations...
  • One explanation may be that as a group, teenagers react more impulsively to threatening situations than do children or adults
  • likely because their brains have to work harder to rein in their behavior
  • teenagers have a reputation for courting danger that is often attributed to immaturity or poor decision-making
  • If immaturity or lack of judgment were the only problem, however, one would expect that children, whose brains are at an even earlier stage of development
  • younger children tend to be more cautious than teenagers, suggesting that there is something unique about adolescent brain development that lures them to danger
  • It's hard to generalize about teenage impulsivity
  • some adolescents clearly have more self-control than many adults
  • a growing body of evidence suggests that, in general, teens specifically struggle to keep their cool in social situations
  • many crimes committed during adolescence involve emotionally fraught social situations
  • to test whether teens perform badly on a common impulsivity task when faced with social cues of threat
  • recruited 83 people, ranging in age from 6 to 29, to perform a simple "Go/No-Go" task
  • they watched a series of faces making neutral or threatening facial expressions flicker past on a computer screen
  • Each time the participants saw a neutral face, they were instructed to hit a button
  • They were also told to hold back from pressing the button when they saw a threatening face
  • As the participants performed the task, the researchers monitored their brain activity with functional magnetic resonance imaging.
  • teenagers made about 15% more errors than adults and children when attempting to stop themselves from pressing the button when they saw the threatening facial expression
  • Males performed worse than females, suggesting a sex difference that fits with the disproportionate number of crimes that male teens commit,
  • adolescents who did manage to restrain themselves showed significantly higher activity in a brain region called the ventromedial prefrontal cortex (vmPFC), which is involved in top-down control of behavior
  • think of it as the break
  • the teenage brain might need to work a little harder to hold that response back
Mars Base

Prospective Alzheimer's drug builds new brain cell connections - 0 views

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scibyte67 Alzheimer

shared by Mars Base on 11 Oct 12 - No Cached
  • researchers have developed a new drug candidate that dramatically improves the cognitive function of rats with Alzheimer's-like mental impairment
  • intended to repair brain damage that has already occurred
  • This is about recovering function
  • ...20 more annotations...
  • t makes these things totally unique. They're not designed necessarily to stop anything. They're designed to fix what's broken. As far as we can see, they work
  • current Alzheimer's treatments, which either slow the process of cell death or inhibit cholinesterase, an enzyme believed to break down a key neurotransmitter involved in learning and memory development
  • Last month, the Pharmaceutical Research and Manufacturers of America, or PhRMA, reported that only three of 104 possible treatments have been approved in the past 13 years
  • Development of the WSU drug is only starting
  • Safety testing alone could cost more than $1 million
  • been working on their compound since 1992
  • practical utility of these early drug candidates, however, was severely limited
  • they were very quickly broken down by the body and couldn't get across the blood-brain barrier,
  • cellular barrier that prevents drugs and other molecules from entering the brain
  • 'That's useless. I mean, who wants to drill holes in people's heads?
  • designed a smaller version of the molecule
  • Not only is it stable but it can cross the blood-brain barrier
  • added bonus is it can move from the gut into the blood, so it can be taken in pill form
  • reported similar but less dramatic results in a smaller group of old rats. In this study the old rats
  • tested the drug on several dozen rats treated with scopolamine, a chemical that interferes with a neurotransmitter critical to learning and memory.
  • a rat treated with scopolamine will never learn the location of a submerged platform in a water tank, orienting with cues outside the tank
  • After receiving the WSU drug, however, all of the rats did, whether they received the drug directly in the brain, orally, or through an injection.
  • statistically valid, additional studies with larger test groups will be necessary to fully confirm the finding.
  • bench assays using living nerve cells to monitor new neuronal connections
  • Dihexa to be seven orders of magnitude more powerful than BDNF, which has yet to be effectively developed for therapeutic use
Mars Base

Auditory test predicts coma awakening | Body & Brain | Science News - 0 views

www.sciencenews.org/...y_test_predicts_coma_awakening

scibyte73 coma

shared by Mars Base on 30 Nov 12 - No Cached
  • A coma patient’s chances of surviving and waking up could be predicted by changes in the brain’s ability to discriminate sounds, new research suggests
  • Recovery from coma has been linked to auditory function before, but it wasn’t clear whether function depended on the time of assessment
  • previous studies tested patients several days or weeks after comas set in
  • ...23 more annotations...
  • new study looks at the critical phase during the first 48 hours
  • At early stages, comatose brains can still distinguish between different sound patterns
  • this ability progresses over time can predict whether a coma patient will survive and ultimately awaken
  • very promising tool for prognosis
  • am led by neuroscientist
  • of the University of Lausanne in Switzerland studied 30 coma patients who had experienced heart attacks that deprived their brains of oxygen
  • All the patients underwent therapeutic hypothermia, a standard treatment to minimize brain damage, in which their bodies were cooled to 33° Celsius for 24 hours
  • played sounds for the patients and recorded their brain activity using scalp electrodes
  • once in hypothermic conditions during the first 24 hours of coma
  • again a day later at normal body temperature
  • sounds were a series of pure tones interspersed with sounds of different pitch, duration or location
  • brain signals revealed how well patients could discriminate the sounds, compared with five healthy subjects
  • After three months, the coma patients had either died or awoken
  • . All the patients whose discrimination improved by the second day of testing survived and awoke from their comas
  • many of those whose sound discrimination deteriorated by the second day did not survive
  • all of the patients showed signs of auditory discrimination
  • suggests that residual auditory function itself does not predict recovery
  • rather, it’s the progression of function over time that is predictive.
  • The study couldn’t distinguish whether auditory function initially was preserved due to the hypothermia treatment or was related merely to the early stage of coma
  • scientists speculate that distracting neural jabber may have been reduced during the hypothermia, making it easier for the patients’ brains to separate sounds
  • now running a follow-up study with 120 coma patients
  • whether the results can be replicated in a bigger population
  • s test could give information about patients who will survive during the first two days of coma
Mars Base

Researchers find clues to how the brain decides when to rest - 0 views

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scibyte80 Learning

shared by Mars Base on 22 Jan 13 - No Cached
  • A team of researchers
  • has found what they call a "signal" that tells a person when to rest while engaging in work, and then when to resume once rested
  • used fMRI scans on a group of volunteers to study a part of the brain normally associated with pain perception and found what amounts to a signal calling for the conscious mind to take a break
  • ...10 more annotations...
  • Scientists studying how people make decisions regarding work have over time devised theories of cost versus benefit scenarios to describe what causes people to engage in work activities, or to not
  • Not so well studied is how people come to decide when it's time to take a break
  • researchers enlisted the aid of 39 participants who were asked to squeeze a spring-loaded handgrip over and over as they underwent fMRI scans
  • Each was promised a monetary reward for doing so based on a sliding scale. The longer they squeezed, the better the reward would be
  • In analyzing the fMRI images, the researchers discovered that activity in a part of the brain called the posterior insula (normally associated with pain perception), built over time as the volunteers continued squeezing – a signal of sorts
  • grew during effort, and then faded during rest times – peaking just before resting
  • researchers suggest that when a certain peak is reached, the rest of the brain is alerted to the need to take a break
  • The team also found that increasing the difficulty of the squeezing led to the signal increasing at a faster rate, but slowed when a bigger reward was offered despite the increased workload
  • They also found that bumping up the reward during a rest period caused the lowest signal point to come more quickly, indicating that rest time was up sooner than it would have been otherwise
  • suggest that their observations indicate that they brain is constantly engaged in a struggle to maximize reward, while simultaneously minimizing the amount of work needed to get that reward, and uses rests stops to help it get there in a manner best suited to the work at hand.
Mars Base

Learning high-performance tasks with no conscious effort may soon be possible (w/ video) - 0 views

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scibyte25

shared by Mars Base on 09 Dec 11 - No Cached
  • New research published today in the journal Science suggests it may be possible to use brain technology to learn to play a piano, reduce mental stress or hit a curve ball with little or no conscious effort
  • Japan, recently demonstrated that through a person's visual cortex, researchers could use decoded functional magnetic resonance imaging (fMRI) to induce brain activity patterns to match a previously known target state and thereby improve performance on visual tasks
  • Think of a person watching a computer screen and
  • ...11 more annotations...
  • brain patterns modified to match those of a high-performing athlete
  • or modified to recuperate from an accident or disease
  • pictures gradually build up inside a person's brain, appearing first as lines, edges, shapes, colors and motion in early visual areas
  • The brain then fills in greater detail
  • none of these studies directly addressed the question of whether early visual areas are sufficiently plastic to cause visual perceptual learning
  • Until now.
  • implemented a method using decoded fMRI neurofeedback to induce a particular activation pattern in targeted early visual areas that corresponded to a pattern evoked by a specific visual feature in a brain region of interest
  • is a novel learning approach sufficient to cause long-lasting improvement in tasks that require visual performance
  • the approached worked even when test subjects were not aware of what they were learning
  • the decoded neurofeedback method might be used for various types of learning, including memory, motor and rehabilitation
  • this study we confirmed the validity of our method only in visual perceptual learning
Mars Base

Decoding the secrets of balance - 0 views

medicalxpress.com/...2012-07-decoding-secrets.html

vertigo GrabBag

shared by Mars Base on 25 Jul 12 - No Cached
  • New understanding of how the brain processes information from inner ear offers hope for sufferers of vertigo
  • vestibular dysfunction such as vertigo and dizziness
  • t a sensory system in the inner ear (the vestibular system) is responsible for helping us keep our balance by giving us a stable visual field as we move around
  • ...10 more annotations...
  • researchers have already developed a basic understanding of how the brain constructs our perceptions of ourselves in motion
  • until now no one has understood the crucial step by which the neurons in the brain select the information needed to keep us in balance.
  • The peripheral vestibular sensory neurons in the inner ear take in the time varying acceleration and velocity stimuli caused by our movement in the outside world
  • These neurons transmit detailed information about these stimuli to the brain
  • in the form of nerve impulses.
  • Scientists had previously believed that the brain decoded this information linearly and therefore actually attempted to reconstruct the time course of velocity and acceleration stimuli
  • by combining electrophysiological and computational approaches
  • two professors
  • have been able to show for the first time that the neurons in the vestibular nuclei in the brain instead decode incoming information nonlinearly as they respond preferentially to unexpected, sudden changes in stimuli.
  • the selective transmission of vestibular information they were able to document for the first time occurs as early as the first synapse in the brain
Mars Base

New energy source for future medical implants: sugar - 0 views

phys.org/...e-future-medical-implants.html

scibyte51 medical FuelCell

shared by Mars Base on 13 Jun 12 - No Cached
  • This silicon wafer consists of glucose fuel cells of varying sizes; the largest is 64 by 64 mm
  • MIT engineers have developed a fuel cell that runs on the same sugar that powers human cells: glucose
  • This glucose fuel cell could be used to drive highly efficient brain implants of the future, which could help paralyzed patients move their arms and legs again
  • ...22 more annotations...
  • strips electrons from glucose molecules to create a small electric current
  • The idea of a glucose fuel cell is not new
  • In the 1970s, scientists showed they could power a pacemaker with a glucose fuel cell, but the idea was abandoned in favor of lithium-ion batteries, which could provide significantly more power per unit area than glucose fuel cells
  • glucose fuel cells also utilized enzymes that proved to be impractical for long-term implantation in the body, since they eventually ceased to function efficiently
  • The new twist
  • is that it is fabricated from silicon, using the same technology used to make semiconductor electronic chips
  • has no biological components
  • consists of a platinum catalyst that strips electrons from glucose
  • mimicking the activity of cellular enzymes that break down glucose to generate ATP
  • So far, the fuel cell can generate up to hundreds of microwatts — enough to power an ultra-low-power and clinically useful neural implant.
  • in theory, the glucose fuel cell could get all the sugar it needs from the cerebrospinal fluid (CSF) that bathes the brain and protects it from banging into the skull
  • are very few cells in the CSF
  • There is also significant glucose in the CSF, which does not generally get used by the body
  • only a small fraction of the available power is utilized by the glucose fuel cell, the impact on the brain’s function would likely be small.
  • the work is a good step toward developing implantable medical devices that don’t require external power sources.
  • ultra-low-power electronics, having pioneered such designs for cochlear implants and brain implants
  • combined with such ultra-low-power electronics, can enable brain implants or other implants to be completely self-powered
  • group has worked on all aspects of implantable brain-machine interfaces and neural prosthetics, including recording from nerves, stimulating nerves
  • decoding nerve signals and communicating wirelessly with implants
  • designed to record electrical activity from hundreds of neurons in the brain’s motor cortex, which is responsible for controlling movement
  • data is amplified and converted into a digital signal so that computers
  • can analyze it and determine which patterns of brain activity produce movement
Mars Base

Study probes why kids with autism are oversensitive to touch, noise - 0 views

medicalxpress.com/...utism-oversensitive-noise.html

scibyte131 Autism

shared by Mars Base on 15 May 14 - No Cached
  • Certain areas in the brains of children with autism overreact to sensory stimuli, such as the touch of a scratchy sweater and loud traffic noises
  • a new small study shows
  • The finding helps to explain why autistic kids are five times more likely than other children to be overwhelmed by everyday sensations
  • ...14 more annotations...
  • It's a condition called sensory over-responsivity, and it was recognized as one of the core features of autism spectrum disorder
  • "I think if anybody ever had a doubt that this was just some sort of odd pickiness or something like that in people with autism, this shows, no, there really is a brain basis for this," said Dr. Paul Wang
  • researchers recruited 32 children and teens. Half the group had been diagnosed with autism. The others were typically developing kids who were matched in age to the autistic kids.
  • scientists had them rest in a fMRI machine, a kind of scanner than can see brain activity in real time
  • they touched the kids with a scratchy wool sweater, played loud traffic noises or did both at the same time. Each condition was repeated four times for 15 seconds
  • The brains of children with autism reacted much more strongly to the sensory stimulation than did the brains of typically developing kids
  • The two areas that seemed to be the most hyperactive were the primary sensory cortex, which is responsible for initially processing sensory information, and the amygdala, which is involved in emotional regulation.
  • They are kind of initially interpreting these stimuli differently and, also, they're not able to regulate their response
  • Shula Green, a Ph.D. candidate
  • typical kids,
  • have an initial response almost immediately, then by the second time around, that response goes way down
  • In kids with autism, that response really stays high throughout the scan. They're not getting used to it
  • the hyperactivity the researchers saw on the brain scans became most intense when kids with autism experienced the two sensations at the same time
  • something is really going on when there's more than one stimulus the brain has to deal with
Mars Base

Study unravels central mystery of Alzheimer's disease - 0 views

medicalxpress.com/...mystery-alzheimer-disease.html

scibyte90 Alzheimer

shared by Mars Base on 11 Apr 13 - No Cached
  • Until recently, Polleux's laboratory has been focused not on Alzheimer's research but on the normal development and growth of neurons
  • In 2011
  • reported that AMPK overactivation by metformin, among other compounds, in animal models impaired the ability of neurons to grow output stalks, or axons
  • ...25 more annotations...
  • Around the same time, separate research groups found clues that AMPK might also have a role in Alzheimer's disease
  • One group reported that AMPK can be activated in neurons by amyloid beta, which in turn can cause a modification of the protein tau in a process known as phosphorylation
  • a postdoctoral research associate
  • began by confirming that amyloid beta, in the small-aggregate ("oligomer") form that is toxic to synapses, does indeed strongly activate AMPK
  • amyloid beta oligomers stimulate certain neuronal receptors, which in turn causes an influx of calcium ions into the neurons
  • that this calcium influx triggers the activation of an enzyme called CAMKK2, which appears to be the main activator of AMPK in neurons
  • AMPK overactivation in neurons is the essential reason for amyloid beta's synapse-harming effect
  • neurons' dendritic spines—the rootlike, synapse-bearing input stalks that receive signals from other neurons
  • scientists showed that amyloid beta oligomers can't cause this dendritic spine loss unless AMPK overactivation occurs—and indeed AMPK overactivation on its own can cause the spine loss
  • the team used J20 mice, which are genetically engineered to overproduce mutant amyloid beta
  • when we blocked the activity of CAMKK2 or AMPK in these neurons, we completely prevented the spine loss
  • Recent studies have shown that amyloid beta's toxicity to dendritic spines depends largely on the presence of tau, but just how the two Alzheimer's proteins interact has been unclear
  • their colleagues are now following up with further experiments to determine what other toxic processes, such as excessive autophagy, are promoted by AMPK overactivation and might also contribute to the long-term aspects of Alzheimer's disease progression
  • also interested in the long-term effects of blocking AMPK overactivation in the J20 mouse model as well as in other mouse models of Alzheimer's disease, which normally develop cognitive deficits at later stages
  • the pharmaceuticals industry who are potentially interested in targeting either CAMKK2 or AMPK
  • show that brain damage in Alzheimer's disease is linked to the overactivation of an enzyme called AMPK
  • Researchers have known for years that people in the earliest stages of Alzheimer's disease begin to lose synapses in certain memory-related brain areas
  • findings, reported in the April
  • Small aggregates of the protein amyloid beta can cause this
  • but how they do so has been a mystery
  • Tangles of tau with multiple phosphorylations ("hyperphosphorylated" tau) are known to accumulate in neurons in affected brain areas in Alzheimer
  • investigate further, to determine whether the reported interactions of AMPK with amyloid beta and tau can in fact cause the damage seen in the brains of Alzheimer's patients
  • In addition
  • findings suggest the need for further safety studies on an existing drug, metformin.
  • , a popular treatment for Type 2 Diabetes, causes AMPK activation.
Mars Base

Early sign of Alzheimer's reversed in lab - 0 views

medicalxpress.com/...ly-alzheimer-reversed-lab.html

scibyte24

shared by Mars Base on 01 Dec 11 - No Cached
  • One of the earliest known impairments caused by Alzheimer's disease - loss of sense of smell – can be restored by removing a plaque-forming protein in a mouse model of the disease
  • study confirms that the protein, called amyloid beta, causes the loss
  • we can use the sense of smell to determine if someone may get Alzheimer's disease, and use changes in sense of smell to begin treatments, instead of waiting until someone has issues learning and remembering
  • ...12 more annotations...
  • We can also use smell to see if therapies are working
  • Smell loss can be caused by a number of ailments
  • since the 1970s, it has been identified as an early sign of this disease
  • There is currently no effective treatment or cure for the disease
  • They found that just a tiny amount of amyloid beta – too little to be seen on today's brain scans - causes smell loss in mouse models
  • Amyloid beta plaque accumulated first in parts of the brain associated with smell, well before accumulating in areas associated with cognition and coordination
  • Despite spending more time sniffing, the mice failed to remember smells and became incapable of telling the difference between odors
  • While losses in the olfactory system occurred, the rest of the mouse model brain, including the hippocampus, which is a center for memory, continued to act normally early in the disease stage
  • Mice were given a synthetic liver x-receptor agonist, a drug that clears amyloid beta from the brain
  • After two weeks on the drug, the mice could process smells normally
  • After withdrawal of the drug for one week, impairments returned
  • team are now following-up on these discoveries to determine how amyloid spreads throughout the brain, to learn methods to slow disease progression
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