Fast prediction of axon behavior

July 20, 2011 in Neuroscience

Researchers at Case Western Reserve University have developed a computer modeling method to accurately predict how a peripheral nerve axon responds to electrical stimuli, slashing the complex work from an inhibitory weeks-long process to just a few seconds.

The method, which enables efficient evaluation of a nerve's response to millions of electrode designs, is an integral step toward building more accurate and capable electrodes to stimulate nerves and thereby enable people with paralysis or amputated limbs better control of movement.

To increase the accuracy of the results, the researchers included a key parameter overlooked in past that were equally fast, but inaccurate. With the new techniques, electrode design can be optimized using advanced algorithms based on natural genetics.

An explanation of the work, which the team hopes others in the field will freely use, and a second method that was simpler and faster but proved less effective, are now available online in the .

"We believe this will allow the next generation of computer-aided development of electrodes," said Dustin Tyler, associate professor of biomedical engineering at Case School of Engineering and senior author of the paper.

Since his graduate school days, Tyler has been developing to stimulate nerves in paralyzed patients and . Taking the large step from animal models to human clinical trials can be improved with better computer modeling, he said.

"Finding the optimal way to stimulate a nerve is kind of like the 'travelling salesman' trying to figure out which is the most efficient route through a group of cities," Tyler said.

Mapping each possible route and figuring the time spent on the road is very difficult to do with a simple equation.

But, using a complex called a genetic algorithm to simultaneously consider all the routes, or in Tyler's predicament electrode designs, and determining the best requires that each design be evaluated in fractions of seconds. This was not possible previously.

The genetic algorithm mimics the process of natural selection, gene recombination and mutation seen in nature. Or, in this case, takes into account which portions of a neuron to stimulate, how much, with how many points of contact, and more variables.

By adding a variable: the magnitude of the voltage outside the cell produced by the electrode, Tyler's group raised the accuracy beyond current techinques.

They used the free-online nerve simulation environment NEURON developed at Yale University. The data the team used is included in the supplemental materials of their paper and may be downloaded for free, said Erik Petersen, a PhD student at Case Western Reserve and lead author. The third author is Oliver Izad, a former master's student in Tyler's lab.

Their method was developed specifically for peripheral motor nerve axons. Nerves cells with different structures, such as those in the brain, spinal cord, or organs are still being investigated.

The researchers are now developing parameters that would take into account these variations in structure to extend the method to work for all of them, further cutting time needed to develop accurate models.

Provided by Case Western Reserve University search and more info website

not rated yet  

Rank not rated yet
Relevant PhysicsForums posts
  • A question about drug tolerance
    createdMay 23, 2012
  • Poor nutrition leading to overeating?
    createdMay 23, 2012
  • Math and dyslexia?
    createdMay 21, 2012
  • portable metabolism meter?
    createdMay 21, 2012
  • Rare medical conditions on 20/20 tonight
    createdMay 18, 2012
  • "Good" Cholesterol in Doubt
    createdMay 17, 2012
  • More from Physics Forums - Medical Sciences

More news stories

Persistent sensory experience is good for aging brain

Despite a long-held scientific belief that much of the wiring of the brain is fixed by the time of adolescence, a new study shows that changes in sensory experience can cause massive rewiring of the brain, even as one ages. ...

Neuroscience created 20 hours ago | popularity not rated yet | comments 0

Boundary stops molecule right where it needs to be

A molecule responsible for the proper formation of a key portion of the nervous system finds its way to the proper place not because it is actively recruited, but instead because it can't go anywhere else.

Neuroscience created 20 hours ago | popularity not rated yet | comments 0 | with audio podcast

Locating ground zero: How the brain's emergency workers find the disaster area

Like emergency workers rushing to a disaster scene, cells called microglia speed to places where the brain has been injured, to contain the damage by 'eating up' any cellular debris and dead or dying neurons. ...

Neuroscience created 20 hours ago | popularity 5 / 5 (2) | comments 0 | with audio podcast

Genetic 'reset switch' enables signaling pathway to induce multiple developmental outcomes for olfactory neurons

Within the nervous system, a handful of signaling pathways modulate development of a cornucopia of different neuronal subtypes. “Even small alterations in neuron differentiation pathways can disrupt subsequent ...

Neuroscience created 23 hours ago | popularity not rated yet | comments 0

The auditory cortex adapts agilely with concentration

The birth of sensory perception on the human cerebral cortex is yet to be fully explained. The different areas on the cortex function in cooperation, and no perception is the outcome of only one area working alone. In his ...

Neuroscience created May 24, 2012 | popularity not rated yet | comments 0


Australia defiant on WTO cigarette challenge

Australia said Friday it would "vigorously defend" itself against complaints about its plan for plain cigarette packaging made by Honduras and Ukraine to the World Trade Organisation.

Chile to cover sex change operations

Chile will soon cover sex change surgeries under its public health plan in order to allow citizens of limited means to "recover their true sexual identity," Health Minister Jaime Manalich said.

Progestin treatment for polycystic ovarian syndrome may reduce pregnancy chances

(Medical Xpress) -- The hormone progestin, often given as a first step in infertility treatment for polycystic ovary syndrome (PCOS), appears to decrease the odds of conception and of giving birth, according to a study by ...

New study should end debate over magnesium treatment for preventing poor outcome after haemorrhagic stroke

An international randomised trial and meta-analysis published Online First in The Lancet should put an end to the debate about the use of intravenous magnesium sulphate to prevent poor outcomes after haemorrhagic stroke. The in ...

World 'no tobacco day' puts spotlight on dangers of smoking

It’s not just smokers who are at-risk when it comes to tobacco smoke exposure—and the health concerns of smoking cigarettes are not limited to the most known consequence: lung cancer. 

Like curry? New biological role identified for compound used in ancient medicine

Scientists have just identified a new reason why some curry dishes, made with spices humans have used for thousands of years, might be good for you.