Posts tagged science
Articles and news from the latest research reports.
If you start exercising, your brain recognizes this as a moment of stress. As your heart pressure increases, the brain thinks you are either fighting the enemy or fleeing from it. To protect yourself and your brain from stress, you release a protein called BDNF (Brain-Derived Neurotrophic Factor). This BDNF has a protective and also reparative element to your memory neurons and acts as a reset switch. That’s why we often feel so at ease and like things are clear after exercising.
Deep Brain Stimulation Changes Rhythms to Treat Parkinson’s Disease and Tremor
ScienceDaily (Aug. 28, 2012) — Deep-brain stimulation (DBS) may stop uncontrollable shaking in patients with Parkinson’s disease and essential tremor by imposing its own rhythm on the brain, according to two studies published recently by University of Alabama at Birmingham researchers in the journal Movement Disorders. An article addressing brain stimulation for essential tremor was published online August 28; a related article on Parkinson’s disease was released May 30.
DBS uses an electrode implanted beneath the skin to deliver electrical pulses into the brain more than 100 times per second. Although this technology was approved by the Food and Drug Administration more than 15 years ago, it remains unclear how it reduces tremor and other symptoms of movement disorders.
With the help of electroencephalography or EEG — electrodes placed on the scalp — study authors used new techniques to suppress the electrical signal associated with the DBS electrode. That enabled the first clear, non-invasive EEG measurements of the underlying brain response during clinically effective, high-frequency brain stimulation in humans.
The results show that nerves in the cerebral cortex, the outer layer of the brain, fire with rapid and precise timing in response to individual stimulus pulses. This suggests that DBS may synchronize the firing of nerve cells and break the abnormal rhythms associated with involuntary movements in Parkinson’s disease and essential tremor.
The newly identified rhythm was captured during effective DBS treatment, so it could represent a new physiological measure of the stimulation dose, say the authors. If validated, such a yardstick could help to guide the fine-tuning of DBS stimulator settings in patients for more lasting relief, fewer side effects and less-frequent battery-replacement surgeries.
"Though it’s clear that more work is needed to better understand these initial observations, we’re very excited by our findings because they may provide a biological marker for improvement in the symptoms of these patients," says Harrison Walker, M.D., assistant professor in the UAB Department of Neurology’s Division of Movement Disorders and lead author of the study.
In current clinical practice, stimulator settings are adjusted by trial and error, requiring careful observation of changes in symptoms over multiple clinic visits. But such immediate, visual feedback may not be available as DBS is applied to neurological or psychiatric conditions such as epilepsy, severe depression or obsessive compulsive disorder. In these diseases, an effective dose measurement could be especially useful in optimizing DBS therapy.
The adult human circulatory system contains between 20 and 30 trillion red blood cells (RBCs), the precise size and number of which can vary from person to person. Some people may have fewer, but larger RBCs, while others may have a larger number of smaller RBCs. Although these differences in size and number may seem inconsequential, they raise an important question: Just what controls these characteristics of RBCs?
By analyzing the results of genome-wide association studies (GWAS) in conjunction with experiments on mouse and human red blood cells, researchers in the lab of Whitehead Institute Founding Member Harvey Lodish have identified the protein cyclin D3 as regulating the number of cell divisions RBC progenitors undergo, which ultimately affects the resulting size and quantity of RBCs. Their findings are reported in the September 14 issue of Genes and Development.
Robots hunt neurons to record brain activity
Devices could reveal inner workings of neurons and how they communicate with each other.
Automated assistance may soon be available to neuroscientists tackling the brain’s complex circuitry, according to research presented last week at the Aspen Brain Forum in Colorado. Robots that can find and simultaneously record the activity of dozens of neurons in live animals could help researchers to reveal how connected cells interpret signals from one another and transmit information across brain areas — a task that would be impossible using single-neuron studies.
A robot that can access the internal workings of neurons could be scaled up to allow 100 cells to be studied at a time. MIT McGovern Institute/E. Boyden/Sputnik Animation
The robots are designed to perform whole-cell patch-clamping, a difficult but powerful method that allows neuroscientists to access neurons’ internal electrical workings, says Edward Boyden of the Massachusetts Institute of Technology in Cambridge, who is leading the work.
Boo! Robots learn to jump like frightened mammals
ROBOTS developed in the safety of a laboratory can be too slow to react to the dangers of the real world. But software inspired by biology promises to give robots the equivalent of the mammalian amygdala, a part of the brain that responds quickly to threats.
(Image: SuperStock)
STARTLE, developed by Mike Hook and colleagues at Roke Manor Research of Romsey in Hampshire, UK, employs an artificial neural network to look out for abnormal or inconsistent data. Once it has been taught what is out of the ordinary, it can recognise dangers in the environment.
For instance, from data fed by a robotic vehicle’s on-board sensors, STARTLE could notice a pothole and pass a warning to the vehicle’s control system to focus more computing resources on that part of the road.
"If it sees something anomalous then investigative processing is cued; this allows us to use computationally expensive algorithms only when needed for assessing possible threats, rather than responding equally to everything," says Hook.
This design mimics the amygdala, which provides a rapid response to threats. The amygdala helps small animals to deal with complex, fast-changing surroundings, allowing them to ignore most sensory stimuli. “The key is that it’s for spotting anomalous conditions,” says Hook, “not routine ones.”
STARTLE has been tested in both vehicle navigation and robot health monitoring. In the latter, it can be trained to respond to danger signs, such as sudden changes in battery power or temperature. It has also been tested in computer networks, as a way to detect security threats, having been trained to identify the pattern of activity associated with an attack.
"A robot amygdala network could be useful," says neuroscientist Keith Kendrick of the University of Electronic Science and Technology of China in Chengdu. "Such a low-resolution analysis will sometimes make mistakes, and you will avoid something needlessly." But a slower, high-resolution analysis is also carried out, he says, which can override the mistakes.
Hooks says that STARTLE could be useful for any robots in complex environments. For example, a robot vehicle would be able to spot other drivers behaving erratically, a major challenge for conventional computing.
Source: NewScientist
Robots that can read and respond to brain waves will eventually help stroke patients regain movement, using new neural interfaces that can re-train damaged motor pathways. Neuroscientists have made great strides in brain-machine interfaces that can respond to a person’s thoughts — a new generation will drive a non-invasive robotic orthotic, retraining the patient’s own body.
Patients who have suffered a stroke or other injury can lose the active use of their limbs, rendering them unable to simply think about moving an arm or hand and then do it. Sometimes it’s possible to re-establish the lost connection, with time and repetitive physical therapy. Researchers at Rice University are using a robotic exoskeleton and a neural interface to improve matters.
Scientists at the University of South Florida (USF), the National Institutes of Health (NIH), Columbia University and the New York State Psychiatric Institute reported that the low-expression form of the gene monoamine oxidase A (MAOA) is associated with higher self-reported happiness in women. No such association was found in men.
The findings appear online in the journal Progress in Neuro-Psychopharmacology & Biological Psychiatry.
Biomarkers May Aid Differential Diagnosis of Dementias, Parkinsonism
Measurements of five protein biomarkers in the cerebrospinal fluid helped to differentiate Alzheimer’s disease from Parkinson’s disease with dementia and from dementia with Lewy bodies in a cross-sectional study of individuals at Swedish neurology and memory disorder clinics.
The diagnostic accuracy of this panel of tests in distinguishing Alzheimer’s disease from dementia with Lewy bodies “is at least in the same order of magnitude as that obtained with dopamine transporter imaging, and with a lower cost,” Dr. Sara Hall of the department of clinical sciences, Lund (Sweden) University, Malmö, and her associates wrote in a study published Aug. 27 in Archives of Neurology.
In addition, one of the five biomarkers in this panel appears to differentiate Parkinson’s disease from atypical parkinsonism such as that seen in progressive supranuclear palsy, multiple system atrophy, or corticobasal degeneration, the researchers noted.
Their results confirmed those of previous studies postulating that CSF total tau (T-tau) and phophorylated tau (P-tau) levels are higher in Alzheimer’s than in the other two dementias, whereas amyloid-beta (Abeta) 1-42 levels are lower in Alzheimer’s than in the other two dementias.
(Source: acep.org)
Proteins adorning the surfaces of human cells perform an array of essential functions, including cell signaling, communication and the transport of vital substances into and out of cells. They are critical targets for drug delivery and many proteins are now being identified as disease biomarkers—early warning beacons announcing the pre-symptomatic presence of cancers and other diseases.
While study of the binding properties of membrane proteins is essential, detailed analysis of these complex entities is tricky. Now, Nongjian (NJ) Tao, Professor of Electrical Engineering, and director of the Center for Bioelectronics and Biosensors at Arizona State University’s Biodesign Institute has devised a new technique for examining the binding kinetics of membrane proteins.
“This is a very important but very difficult problem to solve,” Tao notes. “We demonstrate a new method of approaching the issue, which provides a quantitative analysis of protein interactions on the surface of a cell.”
The technique—known as SPR microscopy—holds the potential to simplify the study of membrane proteins, thereby streamlining the development of new drugs, aiding the identification of diagnostic biomarkers and improving the understanding of cell-pathogen interactions.
The group’s results appear in this week’s advanced online issue of the journal Nature Chemistry.
Neuroscientist David Sulzer Turns Brain Waves Into Music
Columbia neurophysiologist David Sulzer took his first piano lessons at the age of 11 and was playing his violin and guitar in bars by age 15. Later he gained a national following as a founder of the Soldier String Quartet and the Thai Elephant Orchestra—an actual orchestra of elephants in northern Thailand—and for playing with the likes of Bo Diddley, the Velvet Underground’s John Cale and the jazz great Tony Williams.
From left, Brad Garton and David Sulzer discuss turning brain waves into music on WHYY/PBS in Philadelphia.
It was only after arriving at Columbia, however, that the musician-turned-research-scientist embarked on perhaps his most exotic musical venture—using a computer to translate the spontaneous patterns of his brain waves into music.
With the help of Brad Garton, director of Columbia’s Computer Music Center, Sulzer has performed his avant-garde brain wave music in solo recitals and with musical ensembles.
Last spring, Sulzer presented a piece entitled Reading Stephen Colbert at a conference in New York City sponsored by Columbia and the Paris-based IRCAM (Institut de Recherche et Coordination Acoustique/Musique), a global center of musical research.
Sulzer, a professor in the departments of Psychiatry, Neurology and Pharmacology, wore electrodes attached to his scalp to measure voltage fluctuations in his brain as he sat in a chair reading a book by the comedian. Those fluctuations were fed into a computer program created by Garton, which transformed them into musical notes.