High brain centres teach lower brain to adapt to injury

September 30, 1999

Researchers at the University of Toronto have discovered that higher brain centres act as "training wheels" for the lower brain by enabling it to adapt to injury.

In a paper to be published in the October edition of the Journal of Neuroscience, scientists examined the role played by the cerebral cortex - the highest brain centre - in controlling changes commonly observed at lower levels of the nervous system.

"While it has been obvious to scientists for some time that sensory information must flow up each level of the brain, it has always been a puzzle why there is such heavy feedback from higher levels back down to the lower areas of the brain," says Dr. Jonathan Dostrovsky, lead author and professor of physiology at U of T.

Lower brain centres need input from the cerebral cortex initially to adapt to damaged sensory pathways. Once the lower brain centres have been given enough time to adapt to the damage, however, the cerebral cortex is no longer needed to maintain this new re-organized state. In this sense, Dostrovsky says, the cerebral cortex acts much like training wheels for lower brain centres such as the thalamus.

"This sheds new light on the role of the cortex on the thalamus and it could possibly lead to new ways of dealing with strokes or other neurological conditions that involve loss of sensory input," says Dr. Jayson Parker, who conducted this research as part of his PhD thesis at U of T. "These results are still preliminary, but very promising."

Dostrovsky and Parker simulated injury by removing sensory input to the thalamus from the hind limb of laboratory rats, causing the cells of the thalamus to change their properties. This is known as plasticity, a process by which cells modify their properties in response to the removal of sensory input from another part of the body.

"The cortex appears to be necessary to enable these reorganizational changes to take place," Dostrovsky says. "But once it has occurred the cortex is no longer needed for maintaining the new reorganization."

Prof. Dostrovsky's work involves both research and clinical intervention for the management of chronic pain and movement disorders in humans. He was recently named chair of the scientific program committee for the next World Congress on Pain to be held in San Diego in 2002.

This study was funded by the U.S. National Institutes of Health and the Medical Research Council of Canada.
-end-


University of Toronto

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.