New form of brain analysis engages whole brain for the first time

Date:
August 26, 2020
Source:
Duke Department of Neurology
Summary:
A new method of brain imaging analysis offers the potential to
greatly improve the effectiveness of noninvasive brain stimulation
treatment for Alzheimer's, obsessive compulsive disorder,
depression, and other conditions.



FULL STORY ==========================================================================
A new method of brain imaging analysis offers the potential to greatly
improve the effectiveness of noninvasive brain stimulation treatment
for Alzheimer's, obsessive compulsive disorder, depression, and other conditions. Duke researchers developed the new method, which for the
first time analyzed the whole brain network rather than a single region
of the brain. This new method identified brain areas that exert the most control on network function.


==========================================================================
The study, published in the Journal of Neuroscience, has direct
implications for improving the benefits of transcranial magnetic
stimulation, which is currently used for major depression and obsessive compulsive disorder, and may soon lead to therapeutic treatment for
memory disorders such as Alzheimer's and dementia.

Researchers at the Duke Brain Stimulation Research Center (BSRC) developed
a method of analysis that relies on the concept of controllability,
a network principle that helps to predict how one area of the brain
influences a whole network involved in regulating behavior.

The authors measured controllability using functional magnetic
resonance imaging (fMRI) to determine how much change TMS would induce
as participants did a working memory task. In this task, individuals had
to keep bits of information briefly in their memory and manipulate this information in their mind before answering questions about it. This task
was used because of the importance of working memory in everyday life
(like ordering your shopping list in your mind before walking through the grocery store) and because it is highly impacted by aging, particularly
in conditions like Alzheimer's and dementia.

"Essentially, we look at the brain not as a set of discrete islands, but
as a dense web of connections that have lots of mutual influence," said
lead researcher Dr. Simon Davis, PhD, Assistant Professor of Neurology
at Duke.

"Controllability allows us a framework for identifying which nodes in this
web are most likely to be influenced by brain stimulation, and for that
reason likely to show plasticity and improvement after TMS treatments."
The controllability measure, which is based on a static, structural
image of the brain, was used to predict dynamic activity. "Brain
activity is like the spatial pattern of traffic in a city. Although
the traffic pattern is ever- changing, it is always confined by the
topology of the road network," said Lifu Deng, a Duke graduate student
in the Department of Psychology and Neuroscience, and co-lead on the
paper. "Controllability links the stimulation at one location to the
global pattern of brain activity. In our study, for instance, this is
the activation patterns signifying better working memory." Previously,
there has not been a systematic way to identify which brain areas are
the most likely to produce global chances, because most studies have
focused on just one region. This study, however, advanced the field by considering the whole brain network.

While healthy adults participated in the study, the research likely
has implications for memory disorders. "Memory dysfunction as a
network phenomenon that relies on multiple brain regions operating
under coordinated dynamics. The typical focus on the TMS response at
a single site represents a fundamental limitation in the approach of neurostimulation therapies because it neglects global impairments in
whole network that underlies memory dysfunction," said Lysianne Beynel,
PhD, a postdoctoral associate in the BSRC and first author on the study.

Ultimately, this non-invasive brain stimulation method will be used to
promote healthy brain activity patterns and eventually enhance memory
function, which has potential to enhance the efficacy of brain stimulation treatments for a range of cognitive disorders.


========================================================================== Story Source: Materials provided by Duke_Department_of_Neurology. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Lysianne Beynel, Lifu Deng, Courtney A. Crowell, Moritz Dannhauer,
Hannah
Palmer, Susan Hilbig, Angel V. Peterchev, Bruce Luber,
Sarah H. Lisanby, Roberto Cabeza, Lawrence G. Appelbaum,
Simon W. Davis. Structural controllability predicts functional
patterns and brain stimulation benefits associated with working
memory. The Journal of Neuroscience, 2020; JN-RM-0531-20 DOI:
10.1523/JNEUROSCI.0531-20.2020 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200826113710.htm

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