Scientists discover how best to excite brain cells

July 08, 2011

ANN ARBOR, Mich.---Oh, the challenges of being a neuron, responsible for essential things like muscle contraction, gland secretion and sensitivity to touch, sound and light, yet constantly bombarded with signals from here, there and everywhere.

How on earth are busy nerve cells supposed to pick out and respond to relevant signals amidst all that information overload?

Somehow neurons do manage to accomplish the daunting task, and they do it with more finesse than anyone ever realized, new research by University of Michigan mathematician Daniel Forger and coauthors demonstrates. Their findings---which not only add to basic knowledge about how neurons work, but also suggest ways of better designing the brain implants used to treat diseases such as Parkinson's disease---were published July 7 in the online, open-access journal PLoS Computational Biology.

Forger and coauthors David Paydarfar at the University of Massachusetts Medical School and John Clay at the National Institute of Neurological Disorders and Stroke studied neuronal excitation using mathematical models and experiments with that most famous of neuroscience study subjects, the squid giant axon---a long arm of a nerve cell that controls part of the water jet propulsion system in squid.

Among the key findings: Neurons are quite adept at their job. "They can pick out a signal from hundreds of other, similar signals," said Forger, an associate professor of mathematics in the College of Literature, Science and the Arts and a research assistant professor of computational medicine and bioinformatics at the U-M Medical School.

Neurons discriminate among signals based on the signals' "shape," (how a signal changes over time), and Forger and coauthors found that, contrary to prior belief, a neuron's preference depends on context. Neurons are often compared to transistors on a computer, which search for and respond to one specific pattern, but it turns out that neurons are more complex than that. They can search for more than one signal at the same time, and their choice of signal depends on what else is competing for their attention.

"We found that a neuron can prefer one signal---call it signal A---when compared with a certain group of signals, and a different signal---call it signal B---when compared with another group of signals," Forger said. This is true even when signal A and signal B aren't at all alike.

The findings could contribute in two main ways to the design and use of brain implants in treating neurological disorders.

"First, our results determine the optimal signals to stimulate a neuron," Forger said. "These signals are much more effective and require less battery power than what is currently used." Such efficiency would translate into less frequent surgery to replace batteries in patients with brain implants.

"Second, we found that the optimal stimulus is context-dependent," he said, "so the best signal will differ, depending on the part of the brain where the implant is placed."
-end-
The research was funded by the Air Force Office of Scientific Research and the National Institutes of Health

More information:

Daniel Forger---http://www.math.lsa.umich.edu/people/facultyDetail.php?uniqname=forger

PLoS Computational Biology---http://www.ploscompbiol.org/home.action

University of Michigan

Related Neurons Articles from Brightsurf:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.

Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.

A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.

Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.

Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.

Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.

Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.

How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.

Read More: Neurons News and Neurons 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.