Posts tagged neuroscience
Articles and news from the latest research reports.
Stem cells + nanofibers = promising nerve research
Every week in his clinic at the University of Michigan, neurologist Joseph Corey, M.D., Ph.D., treats patients whose nerves are dying or shrinking due to disease or injury.
He sees the pain, the loss of ability and the other effects that nerve-destroying conditions cause – and wishes he could give patients more effective treatments than what’s available, or regenerate their nerves. Then he heads to his research lab at the VA Ann Arbor Healthcare System, where his team is working toward that exact goal.
In new research published in several recent papers (Nature Methods, Biomacromolecules, Materials Science and Engineering) Corey and his colleagues from the U-M Medical School, VAAAHS and the University of California, San Francisco report success in developing polymer nanofiber technologies for understanding how nerves form, why they don’t reconnect after injury, and what can be done to prevent or slow damage.
Using polymer nanofibers thinner than human hairs as scaffolds, researchers coaxed a particular type of brain cell to wrap around fibers that mimic the shape and size of nerves found in the body.
They’ve even managed to encourage the process of myelination – the formation of a protective coating that guards larger nerve fibers from damage. They began to see multiple concentric layers of the protective substance called myelin start to form, just as they do in the body.
(Source: uofmhealth.org)
Musical Training as a Framework for Brain Plasticity: Behavior, Function, and Structure
Musical training has emerged as a useful framework for the investigation of training-related plasticity in the human brain. Learning to play an instrument is a highly complex task that involves the interaction of several modalities and higher-order cognitive functions and that results in behavioral, structural, and functional changes on time scales ranging from days to years. While early work focused on comparison of musical experts and novices, more recently an increasing number of controlled training studies provide clear experimental evidence for training effects. Here, we review research investigating brain plasticity induced by musical training, highlight common patterns and possible underlying mechanisms of such plasticity, and integrate these studies with findings and models for mechanisms of plasticity in other domains.
Caffeine Improves Left Hemisphere Processing of Positive Words
A positivity advantage is known in emotional word recognition in that positive words are consistently processed faster and with fewer errors compared to emotionally neutral words. A similar advantage is not evident for negative words. Results of divided visual field studies, where stimuli are presented in either the left or right visual field and are initially processed by the contra-lateral brain hemisphere, point to a specificity of the language-dominant left hemisphere. The present study examined this effect by showing that the intake of caffeine further enhanced the recognition performance of positive, but not negative or neutral stimuli compared to a placebo control group. Because this effect was only present in the right visual field/left hemisphere condition, and based on the close link between caffeine intake and dopaminergic transmission, this result points to a dopaminergic explanation of the positivity advantage in emotional word recognition.
How connections in the brain must change to form memories could help to develop artificial cognitive computers
Exactly how memories are stored and accessed in the brain is unclear. Neuroscientists, however, do know that a primitive structure buried in the center of the brain, called the hippocampus, is a pivotal region of memory formation. Here, changes in the strengths of connections between neurons, which are called synapses, are the basis for memory formation. Networks of neurons linking up in the hippocampus are likely to encode specific memories.
Medical devices powered by the ear itself
Deep in the inner ear of mammals is a natural battery — a chamber filled with ions that produces an electrical potential to drive neural signals. In today’s issue of the journal Nature Biotechnology, a team of researchers from MIT, the Massachusetts Eye and Ear Infirmary (MEEI) and the Harvard-MIT Division of Health Sciences and Technology (HST) demonstrate for the first time that this battery could power implantable electronic devices without impairing hearing.
The devices could monitor biological activity in the ears of people with hearing or balance impairments, or responses to therapies. Eventually, they might even deliver therapies themselves.
Activating the ‘mind’s eye’ — sounds, instead of eyesight, can be alternative vision
Common wisdom has it that if the visual cortex in the brain is deprived of visual information in early infanthood, it may never develop properly its functional specialization, making sight restoration later in life almost impossible.
Scientists at the Hebrew University of Jerusalem and in France have now shown that blind people – using specialized photographic and sound equipment – can actually “see” and describe objects and even identify letters and words.
The new study by a team of researchers, led by Prof. Amir Amedi of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University and Ph.D. candidate Ella Striem-Amit, has demonstrated how this achievement is possible through the use of a unique training paradigm, using sensory substitution devices (SSDs).
SSDs are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, using a visual-to-auditory SSD in a clinical or everyday setting, users wear a miniature camera connected to a small computer (or smart phone) and stereo headphones.
The images are converted into “soundscapes,” using a predictable algorithm, allowing the user to listen to and then interpret the visual information coming from the camera. The blind participants using this device reach a level of visual acuity technically surpassing the world-agreed criterion of the World Health Organization (WHO) for blindness, as published in a previous study by the same group.
Grid cell firing patterns signal environmental novelty by expansion
The hippocampal formation plays key roles in representing an animal’s location and in detecting environmental novelty to create or update those representations. However, the mechanisms behind this latter function are unclear. Here, we show that environmental novelty causes the spatial firing patterns of grid cells to expand in scale and reduce in regularity, reverting to their familiar scale as the environment becomes familiar. Simultaneously recorded place cell firing fields remapped and showed a smaller, temporary expansion. Grid expansion provides a potential mechanism for novelty signaling and may enhance the formation of new hippocampal representations, whereas the subsequent slow reduction in scale provides a potential familiarity signal.
Young brain develops activity peaks while it is still growing
After a short period of growth, cultured networks of neurons regularly exhibit major activity in the absence of external stimulation. These “bursts” are entirely related to growth. At this stage, they have little to do with learning behaviour, as the network is still too young to sustain a process of memory formation. This has now for the first time been simulated for networks ranging in size from 10,000 to 50,000 neurons. The simulations provide insight into the role of the growth process in initial activity. Researchers at the University of Twente’s MIRA Institute recently published details of this work in PLOS ONE.
Brain study provides new insight into why haste makes waste
Why do our brains make more mistakes when we act quickly?
A new study demonstrates how the brain follows Ben Franklin’s famous dictum, “Take time for all things: great haste makes great waste.”
The research – conducted by Research Assistant Professor Richard Heitz and Jeffrey Schall, Ingram Professor of Neuroscience, at Vanderbilt University – has found that the brain actually switches into a special mode when pushed to make rapid decisions.
The study was published Nov. 7 in the journal Neuron.
How your brain likes to be treated at revision time
If you’re a student, you rely on one brain function above all others: memory.
These days, we understand more about the structure of memory than we ever have before, so we can find the best techniques for training your brain to hang on to as much information as possible. The process depends on the brain’s neuroplasticity, its ability to reorganise itself throughout your life by breaking and forming new connections between its billions of cells.
How does it work? Information is transmitted by brain cells called neurons. When you learn something new, a group of neurons activate in a part of the brain called the hippocampus. It’s like a pattern of light bulbs turning on.
Your hippocampus is forced to store many new patterns every day. This increases hugely when you are revising. Provided with the right trigger, the hippocampus should be able to retrieve any pattern. But if it keeps getting new information, the overworked brain might go wrong. That’s what happens when you think you’ve committed a new fact to memory, only to find 15 minutes later that it’s disappeared again.
So what’s the best way to revise? Here are seven top tips to get information into your brain and keep it there.