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Last Updated: Thursday, November 09, 2006
Challenging theories Inspired
insight
By Becky
Phillips Contributing Writer
Part electrical
engineer and part neurophysiologist, Dave Rector
often will be found tucked in a far corner of the College of
Veterinary Medicine surrounded by a jumble of colored wire, black
electrical tape and socket sets. A slight hint of rodent scents the
air while a periodic table of the elements hangs above a bubbling
lobster tank. Behind his soft-spoken demeanor, Rector’s intensity
and vision give his work a futuristic aura — the projects taking
place in this unlikely laboratory are quietly breaking down
century-old theories in the study of brain function.
As
associate professor in the Department of Veterinary and Comparative
Anatomy, Pharmacology and Physiology (VCAPP) and the Neuroscience
Program, Rector is involved in a number of revolutionary studies.
With his help, a world of often unpleasant medical exams may soon
give way to diagnostics much easier to bear.
Take
scattered-light brain imaging, for example. Studies have shown that
when nerve cells are stimulated, changes take place that can be
measured by bouncing light off the tissue and measuring its
reflectance. It is possible to measure these differences in
reflectance for every physiological state. Someday, instead of the
usual poking and prodding by a doctor or the claustrophobic MRI
experience, you may simply lie down while beams of colored light
scan your body. Causing no discomfort, the light “scatters” off
various tissues and provides a full diagnosis of all brain and body
functions.
“Light can be used as a tool for virtually
anything that medicine has tried to accomplish over the past
millennium,” says Rector. “High-powered lasers are used to cut
tissue during surgery, medium-power laser light can stimulate nerves
and other tissues without damage, and by detecting changes in
low-power light, we can create images of brain activity in three
dimensions. Our ultimate goal is to replace the X-ray, MRI, PET and
CT scan with low-power optical scanning techniques, which are both
less invasive and less expensive.”
Rector and his team have
successfully created surface maps of the rat brain, showing which
parts of the brain are doing what. They plan to begin human brain
mapping in spring 2007 using a special helmet that contains hundreds
of fiber optic connections — or optrodes — that attach to the scalp.
Assisting him in this effort are Jennie
Schei, graduate student in physics, and Amanda
Foust, senior in neuroscience. Also involved in the design
process are Matt McCluskey, associate professor and
chair of the Department of Physics, and George La
Rue, associate professor, and Deuk Heo,
assistant professor, both in the Department of Electrical
Engineering.
Their plan is to develop a helmet that can
perform both functional and structural brain imaging and diagnosis.
Funded by the National Institute of Mental Health, Rector’s team
expects to have a functional prototype available to the public
within the next two to three years.
Sleeping
cortical columns The helmet also will be used to image
the brain continuously during sleep — specifically measuring
activity in the cortical columns, which has never been done before.
This is not surprising since it was Rector, together with
Jim Krueger, professor in VCAPP, who recently
discovered that the brain does not sleep all at once; rather, it
sleeps in variable shifts of related brain cells called cortical
columns.
In essence, different parts of the brain can be
asleep at different times. Those brain cells that have been required
to work the hardest are the first to enter the sleep state. When
enough cortical columns “fall asleep,” the whole animal/person goes
to sleep.
Though it had been previously shown that half of
the brain can sleep independently of the other half in marine
mammals, Rector’s discovery is groundbreaking in that he has
identified the smallest unit of the brain that actually
sleeps.
Through use of the optical helmet, Rector and his
colleagues — in collaboration with Greg Belenky and
Hans VanDongen at the WSU Spokane Sleep and
Performance Research Center — hope to detect when different parts of
the human brain are tired and from there predict when mistakes are
more likely to be made. In the future, people in occupations from
truck driver to flight controller may use similar technologies to
plan safe and effective work schedules.
The brain as
a hologram To break it down even further, Rector is
proposing that the brain no longer be thought of as a circuit with
wires, but as a substrate for electromagnetic waves — or a hologram.
In a study funded by the Beckman Foundation in 2003, Rector drew
from the observations of others to create a new theory of basic
brain function. He is proposing that the purpose of the brain is to
set up electromagnetic “standing” waves in response to
stimulation.
This is something like when two pebbles
are thrown into a pond. The ripples — waves — intersect and lead to
sensory perception. “As holograms change their
appearance when looked at from different angles,” said Rector, “so
would the electromagnetic waves in the brain create different
perceptions with each experience.”
This theory is evident in
the 3-D videos his lab has recorded of standing waves in rat brains.
The size and amplitude of the wave varies in response to precise
stimuli, such as individual whiskers being
twitched.
Practically speaking, this idea may revolutionize
the way medicine deals with brain disease.
“The theory
of the brain operating as an electrical circuit does not always
explain the results of brain injury or disease. In many cases, there
is damage to a specific area of the brain, but people recover and do
just fine,” Rector said.
“Looking at the brain as a
hologram may allow doctors to become much more effective in treating
disease — potentially developing stimulation protocols to match an
individual’s brain waves and thereby creating prosthetics for any
neurological function in the body.”
Family, church,
community Research is demanding, and those who do it may
struggle to balance time between work and the rest of life. It’s no
different for Dave Rector, who spends countless hours in his
laboratory each week. Yet with the support of his wife and love of
his two young children, he has managed to place family and community
high on his list of priorities.
An active leader in
Pullman’s Emmanuel Baptist Church, his faith motivates his vocation.
“One of the reasons I was interested in becoming a scientist
was to learn more about God’s creation — and my position in the
university helps me to remain open-minded.”
Community
activities: • President, Montessori school board •
Leads 4th-grade AWANA (Bible/activities) class, Emmanuel Baptist
Church • Leads small-group Bible study/fellowship, Emmanuel
Baptist Church
Craftsmanship What do you
do when your research ideas outrun the current technology? In Dave
Rector’s case, he walks across the hall to his machine shop and
builds that circuit board or miniature implantable video camera.
“We can’t fabricate microcircuits,” he concedes. “We
have to send out for those. But for everything else, if we can buy
the components, we can build it.”
As if for inspiration, the
first computer he built at age 10 hangs on the wall above his desk.
Scattered below it are mounds of handcrafted devices ranging from
simple brackets to the most intricate electronics.
Among
them is a tiny photodiode used for making optical measurements —
much like a camera. The device is implanted in freely moving rats to
measure photon (the basic unit of light) production at sunrise each
morning. It is then that a certain gene — similar to one found in
fireflies and coupled to the rat’s circadian rhythm gene — activates
and causes every living cell in the animal to glow fluorescent
green.
By measuring the emitted photons, Rector and
colleague Heiko Jansen, assistant professor in
VCAPP, hope to better understand how daily physiological cycles
affect sleep and lead to problems such as jet lag.
In
another project, funded by the National Institute of Mental Health,
Rector — together with electrical engineers George La Rue and Deuk
Hoe — has developed a tiny 16-channel physiological amplifier on a
chip.
“This amplifier currently outperforms any existing
amplifier in the world,” said Rector, “and it has a built-in
computer system, with a high-speed wireless transmitter, for
converting electrical and optical signals into digital data.” It is
this amplifier that will be connected to hundreds of similar chips
for use in the optical imaging helmet the team has developed for
scanning human brain function.
“We call this our
neurophysiological diagnostic laboratory in a helmet,” Rector said.
“With it, we should be able to handle and process any type of
physiological information such as EEGs and scattered-light
readings.”
Commitment to education For
researchers intent on winning grants and publishing papers, teaching
sometimes takes a back seat. But according to Bryan
Slinker, professor and chair of VCAPP and director of
neuroscience, Dave Rector specifically chose to come to WSU for the
value the institution places on undergraduate and graduate
education.
“Dave is also highly committed to K-12 outreach,”
he said. “For example, he has long overseen the Neuroscience Program
KidsJudge!, an event for fifth graders during Brain Awareness
Week.”
Rector recently submitted a grant to the Howard Hughes
Medical Institute to fund a “Role Models for Science” program, in
which researchers would mentor K-12 students with their science-fair
projects. And he hopes to participate in the Pipeline Program, a
statewide WSU outreach to interest and graduate more students in
science and math. It is being submitted to the Washington
Legislature by WSU in the 2007 session.
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