Reorganization of brain area for vision after stroke: May yield new treatments for brain injurySeptember 05, 2007New evidence from a patient shows that the area of the brain that processes visual inputs can reorganize after an injury caused by stroke. Scientists found that a brain region that had stopped receiving signals from the eyes because of a stroke began responding to signals formerly processed in adjacent brain areas. This finding demonstrates plasticity, the ability of a brain area to change its functioning, in the adult human brain. The finding will not lead immediately to treatments, but may eventually play a role in designing new therapies to aid recovery following stroke and brain injury, say the authors, whose study appears in the September 5 issue of The Journal of Neuroscience. "The results shed light on the ability of the adult human brain to reorganize itself and on the functional consequences of such reorganization," says Shimon Ullman, PhD, of the Weizmann Institute of Science in Israel. "Considerable plasticity of the brain has been demonstrated in various animals and different brain regions, but relatively little has been known about such reorganization processes of the human visual system." Ullman was not involved in the study. Daniel Dilks, PhD, of Massachusetts Institute of Technology, and colleagues studied a 51-year-old man six months after he suffered a stroke. It damaged nerve fibers that transmitted information from his eye to one region of his visual cortex, which processes visual inputs, rendering him partially blind. The cortex itself was not injured.
Below the blind area, the subject reported that objects looked distorted. For example, when a square appeared just below the blind area, he perceived the square as a rectangle extending upward into the blind area. Testing conducted over a period of four years revealed that the cortex was responding to visual signals normally processed in the adjacent region, suggesting it had been reorganized. "We discovered that it took on new functional properties, and he sees differently as a consequence of that cortical reorganization," Dilks said. Functional magnetic resonance imaging studies confirmed that the visually deprived cortex, which formerly responded only to information coming from the upper left visual field, was now responding to information from the lower left visual field. Future research will examine exactly which neural mechanisms in the cortex are reorganized and how. One focus of the research will be the connections that link adjacent regions in the visual cortex. Society for Neuroscience | |||||||||||||||||||||
|
Related Brain Injury Current Events and Brain Injury News Articles Oh, what a feeling! People who have lost the ability to interpret emotion after a severe brain injury can regain this vital social skill by being re-educated to read body language, facial expressions and voice tone in others, according to a new study. New insight into the controls on a go-to enzyme Scientists at St. Jude Children's Research Hospital have gained new insights into regulation of one of the body's enzyme workhorses called calpains. Simple brain mechanisms explain arbitrary human visual decisions Mark Twain, a skeptic of the idea of free will, argues in his essay "What Is Man?" that humans do not command their minds or the opinions they form. Ultrasound shown to exert remote control of brain circuits In a twist on nontraditional uses of ultrasound, a group of neuroscientists at Arizona State University has developed pulsed ultrasound techniques that can remotely stimulate brain circuit activity. A new relationship between brain derived neurotrophic factor and inflammatory signaling In the October 14th edition of Science Signaling researchers at Boston University School of Medicine (BUSM), The Children's Hospital of Philadelphia/University of Pennsylvania School of Medicine and The University of Colorado Denver School of Medicine have shown that the development of epilepsy in adult rats is linked to functional changes in the expression of alpha 1 containing GABA-A receptors, the main inhibitory neurotransmitter receptor in the brain, that may be dependent upon BDNF-induced activation of the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Direct recording shows brain signal persists even in dreamless sleep Neuroscientists at Washington University School of Medicine in St. Louis have taken one of the first direct looks at one of the human brain's most fundamental "foundations": a brain signal that never switches off and may support many cognitive functions. Duke team finds compounds that prevent nerve damage Duke University Medical Center scientists have made a significant finding that could lead to better drugs for several degenerative diseases including Huntington's disease and Alzheimer's disease. New marker for raised intracranial pressure Magnetic resonance imaging (MRI) measurements of the thickness of the optic nerve sheath are a good marker for raised intracranial pressure (ICP). Rapid changes in key Alzheimer's protein described in humans For the first time, researchers have described hour-by-hour changes in the amount of amyloid beta, a protein that is believed to play a key role in Alzheimer's disease, in the human brain. Pregnancy situations have impact on brain development in pre-term infants Brain development in infants who are born very prematurely is still incomplete. Factors that cause premature birth may have an impact on the development of the premature infant's brain both during pregnancy and later on after birth. More Brain Injury Current Events and Brain Injury News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||