Stroke Damage in Mice Overcome by Training that ‘Rewires’ Brain Centers

Johns Hopkins researchers have found that mice can recover from physically debilitating strokes that damage the primary motor cortex, the region of the brain that controls most movement in the body, if the rodents are quickly subjected to physical conditioning that rapidly “rewires” a different part of the brain to take over lost function.

Their research, featuring precise, intense and early treatment, and tantalizing clues to the role of a specific brain area in stroke recovery, is described online in the journal Stroke.

"Despite all of our approved therapies, stroke patients still have a high likelihood of ending up with deficits," says study leader Steven R. Zeiler, M.D., Ph.D., an assistant professor of neurology at the Johns Hopkins University School of Medicine. "This research allows us the opportunity to test meaningful training and pharmacological ways to encourage recovery of function, and should impact the care of patients."

With improved acute care for stroke, more patients are surviving. Still, as many as 60 percent are left with diminished use of an arm or leg, and one-third need placement in a long-term care facility. The economic cost of disability translates to more than $30 billion in annual care.

Sleep and dreaming: The how, where and why

Within a few hours of reading this you will lose consciousness and slip into a strange twilight world. Where does your mind go during that altered state – or more accurately states – we call sleep? And what is so vital about it that we must spend a third of our lives sleeping? In these articles, we review the latest ideas on why we sleep and look at new ways to enhance its benefits.

Damaged Blood Vessels Loaded with Amyloid Worsen Cognitive Impairment in Alzheimer’s Disease

A team of researchers at Weill Cornell Medical College has discovered that amyloid peptides are harmful to the blood vessels that supply the brain with blood in Alzheimer’s disease — thus accelerating cognitive decline by limiting oxygen-rich blood and nutrients. In their animal studies, the investigators reveal how amyloid-ß accumulates in blood vessels and how such accumulation and damage might be ultimately prevented.

Their study, published in the Feb. 4 online edition of the Proceedings of the National Academy of Sciences (PNAS), is the first to identify the role that the innate immunity receptor CD36 plays in damaging cerebral blood vessels and promoting the accumulation of amyloid deposits in these vessels, a condition known as cerebral amyloid angiopathy (CAA).

Importantly, the study provides the rational bases for targeting CD36 to slow or reverse some of the cognitive deficits in Alzheimer’s disease by preventing CAA.

"Our findings strongly suggest that amyloid, in addition to damaging neurons, also threatens the cerebral blood supply and increases the brain’s susceptibility to damage through oxygen deprivation," says the study’s senior investigator, Dr. Costantino Iadecola, the Anne Parrish Titzell Professor of Neurology at Weill Cornell Medical College and director of the Brain and Mind Research Institute at Weill Cornell Medical College and NewYork-Presbyterian Hospital. "If we can stop accumulation of amyloid in these blood vessels, we might be able to significantly improve cognitive function in Alzheimer’s disease patients. Furthermore, we might be able to improve the effectiveness of amyloid immunotherapy, which is in clinical trials but has been hampered by the accumulation of amyloid in cerebral blood vessels."

Mounting scientific evidence shows that changes in the structure and function of cerebral blood vessels contribute to brain dysfunction underlying Alzheimer’s disease, but no one has truly understood how this happens until now.

Molecule key to sustaining brain communication

Scientists have discovered the powerful role the molecule Myosin VI plays in communication between nerve cells in the brain.

Researchers at the University of Queensland’s (UQ) Queensland Brain Institute (QBI) have found that Myosin VI is integral to maintaining the neurotransmitter release that allows neurons to pass on information to other neurons.

The discovery made by Vanesa Tomatis, a PhD student in Associate Professor Frederic Meunier’s laboratory, demonstrates how Myosin VI has the impressive ability to anchor secretory vesicles that are at least 5,000 times greater in size, near their release site.

"By tethering and anchoring secretory granules, Myosin VI helps to maintain an active pool of vesicles near the plasma membrane, which is key to sustaining communication between neuronal cells," Associate Professor Meunier said.

Associate Professor Meunier and his team are now looking to better understand how the Myosin VI manages to grab and hold vesicles through the use of super resolution microscopy.

They hope the discovery will lead to new ways to reinstate or regulate neuronal communication in various brain disorders.

The paper was published in The Journal of Cell Biology on February 4 2013

(Image credit: Wikipedia)

Pioneering research helps to unravel the brain’s vision secrets

A new study led by scientists at the Universities of York and Bradford has identified the two areas of the brain responsible for our perception of orientation and shape.

Using sophisticated imaging equipment at York Neuroimaging Centre (YNiC), the research found that the two neighbouring areas of the cortex — each about the size of a 5p coin and known as human visual field maps — process the different types of visual information independently.

The scientists, from the Department of Psychology at York and the Bradford School of Optometry & Vision Science established how the two areas worked by subjecting them to magnetic fields for a short period which disrupted their normal brain activity. The research which is reported in Nature Neuroscience represents an important step forward in understanding how the brain processes visual information.

Attention now switches to a further four areas of the extra-striate cortex which are also responsible for visual function but whose specific individual roles are unknown.

The study was designed by Professor Tony Morland, of York’s Department of Psychology and the Hull York Medical School, and Dr Declan McKeefry, of the Bradford School of Optometry and Vision Science at the University of Bradford. It was undertaken as part of a PhD by Edward Silson at York.

Researchers used functional magnetic resonance imaging (fMRI) equipment at YNiC to pinpoint the two brain areas, which they subsequently targeted with magnetic fields that temporarily disrupt neural activity. They found that one area had a specialised and causal role in processing orientation while neural activity in the other underpinned the processing of shape defined by differences in curvature.

(Photo: Image courtesy of Brian A. Wandell, Serge O. Dumoulin and Alyssa A. Brewer)

Propping Open the Door to the Blood Brain Barrier

The treatment of central nervous system (CNS) diseases can be particularly challenging because many of the therapeutic agents such as recombinant proteins and gene medicines are not easily transported across the blood-brain barrier (BBB). Focused ultrasound can be used to “open the door” of the blood brain barrier. However, finding a way to “prop the door open” to allow therapeutics to reach diseased tissue without damaging normal brain tissue is the focus of a new study by a team of researchers at the Institute of Biomedical Engineering at National Taiwan University presenting at the 57th Annual Meeting of the Biophysical Society (BPS), held Feb. 2-6, 2013, in Philadelphia, Pa.

The group is investigating the feasibility of using heparin, a common anticoagulant, to enhance the delivery of therapeutic macromolecules using ultrasound into the brain. Heparin could be employed to increase treatment efficacy in patients with different types of CNS diseases under the guidance of medical imaging system providing new hope in these challenging cases. Initial results show that heparin does have the potential to optimize therapeutic delivery with ultrasound, acting as a “doorstop,” allowing drugs to better permeate the BBB and enhancing treatment success.

“A higher acoustic pressure and longer sonication, and/or a higher dose of microbubbles may increase the delivery of drugs or tracers into the sonicated brain tissue,” explains Kuo-Wei Lu, a member of the research team, “but side-effects, such as microhemorrhage, can also increase dramatically. The results of this study indicate that heparin may offer a safer way can to enhance the delivery of therapeutics to patients with CNS diseases.”

With these encouraging results, the next step for the team is to develop a focused ultrasound system with Magnetic Resonance Imaging (MRI) guidance to establish suitable parameters needed for patient clinical trials. “Focused ultrasound sonication is a noninvasive technology capable of localized and transient BBB opening for the delivery of CNS therapeutics,” Lu states. “We hope by developing suitable parameters and using chemical enhancers like heparin, this can be a valuable tool in the treatment of patients with CNS diseases, opening the door to better patient outcomes.”

(Image: Ben Brahim Mohammed)

City Life Changes How Our Brains Deal With Distractions

City life requires a lot of attention. Navigating a busy sidewalk while processing loud storefronts and avoiding rogue pigeons may feel like second-nature at times, but it’s actually quite a bit of work for the human brain. Psychologists do know that quick walks through the park can restore our focus, but they’re still getting a handle on just what urbanization means for human cognition.

A new series of behavioral studies offers some of the richest evidence to date on the mental exhaustion of urban living. In an upcoming issue of the Journal of Experimental Psychology: Human Perception and Performance, a group of British psychologists reports that people who live in cities show diminished powers of general attention compared to people from remote areas. With so much going on around them, urbanites don’t pay much attention to surroundings unless they’re highly engaging.

Cognitive Connectivity

Credit: Emmett McQuinn, Theodore M. Wong, Pallab Datta, Myron D. Flickner, Raghavendra Singh, Steven K. Esser, Rathinakumar Appuswamy, William P. Risk, and Dharmendra S. Modha; IBM Research - Almaden  -(First place winners in the illustration category of the 2012 International Science & Engineering Visualization Challenge)

Cognitive Computing researchers at IBM are developing a new generation of “neuro-synaptic” computer chips inspired by the organization and function of the brain. For guidance into how to connect many such chips in a large brain-like network, they turn to a “wiring diagram” of the monkey brain as represented by the CoCoMac database. In a simulation designed to test techniques for constructing such networks, a model was created comprising 4173 neuro-synaptic “cores” representing the 77 largest regions in the macaque brain. The 320749 connections between the regions were assigned based on the CoCoMac wiring diagram. This visualization is of the resulting core-to-core connectivity graph. Each core is represented as an individual point along the ring; their arrangement into local clusters reflects their assignment to the 77 regions. Arcs are drawn from a source core to a destination core with an edge color defined by the color assigned to the source core.