Summary-- University at Buffalo scientists have used
magnetic nanoparticles to remotely control ion channels, neurons in
cell culture and even the movement of a tiny worm.
-- A new $1.3 million grant will enable the UB team to test the
technique on neurons in the brains of mice. Remote
neuro-stimulation would help scientists learn how neuronal
circuitry governs behavior, leading to better treatment of human
ailments, such as traumatic brain injuries.
BUFFALO, N.Y. -- Scientists at the University at Buffalo have
received $1.3 million from the National Institute of Mental Health
(NIMH) to test how tiny, magnetic particles can be used to remotely
control neurons in the brains of mice.
If the work is successful, the research team will have given
neuroscientists a powerful, new tool: a non-invasive technique for
triggering activity deep inside the brain.
This kind of remote, neuro-stimulation would help researchers
learn more about how the brain's complicated neuronal circuitry
controls behavior, leading eventually to better understanding and
possibly treatment of ailments that involve the injury or
malfunction of specific sets of neurons. Traumatic brain injuries,
Parkinson's disease, dystonia and peripheral paralysis all fall
into this category.
"Our early understanding about the brain's functional regions
came from patients who showed changes in their behavior after
losing a part of their brain to traumatic brain injury or a tumor,"
said Arnd Pralle, the assistant professor of physics who is leading
the new UB study. "The ability to now reversibly turn individual
cells off or on and to observe the animal's behavior brings us
finally to the level of the actual neurological circuit, which is
The new NIMH funding, which comes from the National Institute of
Health's program for Exceptional, Unconventional Research Enabling
Knowledge Acceleration (EUREKA), is a testament to the promise of
He and his colleagues have already succeeded in using their
remote control technique to open calcium ion channels, activate
neurons in cell culture, and even manipulate the behavior of C.
elegans, a tiny worm.
The approach involves the use of heated, magnetic nanoparticles
in conjunction with some clever genetic engineering.
Here's how it works in the brain: First, scientists employ
harmless viruses to carry a special strand of DNA into the brain.
The new genetic material induces specific, targeted cells to build
a special ion channel containing a receptor that magnetic
nanoparticles will recognize.
When the nanoparticles latch onto these ion channels, scientists
apply an alternating magnetic field to the brain that causes the
particles' magnetization to flip rapidly, generating heat. That
heat then stimulates the ion channels to open, depolarizing the
neurons and causing them to fire.
With the new NIMH funding, Pralle's research team plans to test
this method on neurons in the olfactory bulb, which lies in the
forward region of the brain and controls how animals perceive
Specifically, the scientists will see if they can use the
nanoparticles' localized heating to activate specific neurons in
the olfactory bulb, causing the mice to "smell" a particular odor
even when no actual chemicals are present.
As neuroscientists search for better ways to probe the brain,
Pralle's method is particularly attractive because magnetic fields
are able to penetrate tissues without harming them. Other methods
for remotely controlling brain cells are more invasive, including a
state-of-the-art technique involving the use of an implanted
optical fiber to stimulate light-activated ion channels.
Pralle's prior work on magnetic nanoparticles was supported by
the UB 2020 Interdisciplinary Research Development Fund, which
provides start-up money to projects with the potential to receive
larger, external grants.
That seed funding enabled Pralle and his collaborators to
complete a number of studies, including one in which they attached
magnetic nanoparticles to cells near the mouth of C. elegans.
When the scientists used their remote technique to heat the
nanoparticles, most of the worms began reflexively crawling
backward in an attempt to escape the heat when the temperature hit
34 degrees Celsius.
The university is in full compliance with mandates of state and
federal regulatory agencies pertaining to the humane use and care
of research animals.
The University at Buffalo is a premier research-intensive public
university, a flagship institution in the State University of New
York system and its largest and most comprehensive campus. UB's
more than 28,000 students pursue their academic interests through
more than 300 undergraduate, graduate and professional degree
programs. Founded in 1846, the University at Buffalo is a member of
the Association of American Universities.
With Magnetic Nanoparticles, Scientists Remotely Control Neurons
and Animal Behavior: http://www.buffalo.edu/news/11518
Nature Nanotechnology News and Views on "Magnetogenetics": http://www.nature.com/nnano/journal/v5/n8/full/nnano.2010.163.html