Exactly how f*cking long is it going to take your doctor to update your stroke protocols to take in this new information? Or never?
http://www.alphagalileo.org/ViewItem.aspx?ItemId=148476&CultureCode=en
Scientists at the RIKEN Center for Life Science Technologies, along
with researchers from the AIST Human Technology Research Institute in
Japan, have identified a time-dependent interplay between two brain
regions that contributes to the recovery of motor function after focal
brain damage, such as a stroke. Published in the Journal of
Neuroscience, the research shows that when motor functions are remapped
through rehabilitative training, brain regions relatively distant from a
lesion are recruited during the initial stages and functional
connections with regions near the lesion are strengthened during the
latter stages.
The research team investigated the special kind of neural plasticity
that allows the recovery of motor function after brain damage, focusing
on changes that occur during the course of rehabilitative training. This
kind of training is known to promote structural and functional
alterations in the brain that improve impaired motor ability, but how it
does so is a question that neuroscientists are still trying to answer.
The team studied the rehabilitation process in monkeys that had
suffered injury to the region of the cerebral cortex that controls hand
movements. This region of the primary motor cortex is especially needed
for fine movements, such as those required to grip and manipulate small
objects using fingers. To facilitate recovery of motor function, the
researchers taught monkeys to quickly and repeatedly grab a piece of
potato through a small opening using their thumbs and index fingers—a
task that requires a high degree of manual dexterity.
As expected, the team found that performing this task 30 minutes a
day for several weeks after injury resulted in greatly improved motor
function. To estimate changes in brain activity associated with the
recovery, they imaged the regional brain activity using H215O-positron
emission tomography (PET) before injury and at the early and late stages
of recovery while monkeys performed the task. They found that activity
in the ventral premotor cortex—a brain region somewhat distant from the
injury—was higher during the early stage of recovery than before the
injury. They also conducted what is known as a psychophysiological
interactions (PPI) analysis and found that when monkeys performed the
task in the later stages of recovery, connections between the lesion
site and regions of primary motor cortex immediately surrounding it
became stronger.
To verify whether the changes in these regions were in fact necessary
for the recovery, they temporarily inactivated them before injury and
at the recovery stages. They found that inactivation of the ventral
premotor region on the same side of the brain as the lesion impaired
precision grip during the early stages of recovery— even when it was
limited to regions that had not been essential to hand movements before
the injury. They also found that the area surrounding the injury became
devoted to movements related to precision grip. During the later stage
of recovery, inactivating this area only affected precision grips, but
not other types of grips that had been impaired by inactivation before
the lesion.
When explaining their excitement for these new findings, Yumi Murata
from AIST noted that, “they will likely contribute to the development of
new rehabilitation techniques and drugs, as well as new ways to
evaluate rehabilitative training.” Hirotaka Onoe from RIKEN added that
“new rehabilitation techniques will help reduce the burden that these
types of strokes have on the patients and their families.”
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