7/27/2019 articles-decode the brain.pdf

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Doctors know that they can control epileptic

seizures without having to perform surgeryby placing the patients brain in an electricfield.In doing so, they are exploiting the factthat an electric field can cause neurons tofire in synchrony. But they do not under-stand exactly how the process works. Eun-Hyoung Park, a research associate at theNeural Engineering Center at Case West-ern Reserve University in the US, believesthat is important to understand the way inwhich the neurons respond to the field.This is an area where mathematiciansand physicists can help,she says.You needto understand why these therapies work.

Park is one of a growing number of re-

searchers who have opted to apply theirphysics training to problems in neurosci-ence. Park initially completed a PhD andpostdoctoral work in chaos theory andphase synchronization. She then moved toCase Western to apply the same theoreticaltools to medical applications. I wanted toexpand my knowledge into a more appliedfield, she says. Synchronization prevails innature in a lot of different areas.

Dominique Durand, editor in chief of anewJournal of Neural Engineeringpublishedby the Institute of Physics, believes that thecontribution of physical scientists and en-

gineers is crucial to understanding thebrain.While neuroscientists and engineersfrom varied fields such as brain anatomy,neural development and electrophysiologyhave made great strides in the analysis ofthis complex organ, there remains a greatdeal yet to be uncovered, he says. Thepotential for applications and remediesderiving from scientific discoveries andbreakthroughs is extremely high.

Denis le Bihan,director of the Institute ofFunctional Neuroimaging, in Paris, agreesthat physicists theories are critical to ad-

vancing treatment of neurological and psy-

chiatric disorders. Models and tools usedtoday in high-energy physics could showhow clusters of neurons work together, hesays. In fact, the secrets of the brain couldbe in the hands of physicists.

Le Bihans perspective on interdisciplin-ary collaboration is aided by his dual back-ground in medicine and physics; he leftcollege as a qualified medical doctor andwith a PhD in physics. He has subsequentlyemerged as a world authority on magneticresonance imaging (MRI), developing pion-eering techniques to study acute brain dis-eases and connectivity disorders.

Le Bihan is currently overseeing plans for

a new neuroimaging centre within the re-

search campus of the French atomic energycommission (CEA) on the outskirts of Paris.The NeuroSpin complex will house fourultrahigh-field MRI units suitable forhuman and animal studies. The state-of-the-art scanners will offer sufficient spatialresolution to visualize neurons and neuronalconnections directly. Scanner access will besplit between full-time staff members andresearchers from other institutions who havebought time slots, a concept more familiar

to physicists than biological neuroscientists.I do not say that NeuroSpin is exactly likeCERN, but it provides a good workingmodel for sharing large, expensive equip-ment,says le Bihan.

Learning from biologyPhysicists have much to learn from their col-leagues in biological neuroscience too. Inphysics you always try to use a simple modelto explain experimental results, but neuro-scientists always try to simulate everything indetail.They want a real model,not a simplemodel, says Jianwei Shuai, a neurologist

at the University of California, Irvine, whooriginally did a PhD in theoretical physics.He now uses tools from nonlinear dynamicsto model the way cells communicate via cal-cium signalling. A lone theorist in a laborat-ory of experimentalists, Shuai now regardshimself as both a physicist and neurosci-entist.Yet it took a good three years to com-plete the philosophical transition, he says.

Zhaoping Li, reader in psychology andhonorary reader in physics at UniversityCollege London, is equally adamant thatphysicists should adopt an alternative mind-set when moving into neuroscience. Wheninterviewing prospective postdoctoral stu-

dents, she quizzes them if they expect to be

asking original questions about neurological

systems themselves. This is not a fieldwhere other people ask the questions andyou just solve them. You need to ask thequestions yourself. Open your mind to bemore ambitious, she says.

But this more creative approach can bequite daunting at first, says John Hertz,pro-fessor of biophysics at the Nordic Institute ofTheoretical Physics in Copenhagen. Hertztrained in statistical physics and condensed-matter physics before becoming interestedin disordered systems and eventually bio-logical information processing. He workedfirst on spin glasses, systems with a highlyirregular magnetic configuration. Spotting

an analogy with neural circuitry, he thenstarted to apply his ideas on magnetic sys-tems to model memory. Initially I really feltI was too ignorant about real neuroscienceto dare say much about it. But gradually Igot more confident, he says.

Opening doors and mindsExperimentalists are also benefiting fromcloser collaboration with their theoreticalcolleagues, and recognizing the import-ance of theory within their discipline. Inthe old days, experimental neurobiologistsnever read any theoretical papers. Every-

body assumed they could do their own the-ory. But now people are realizing that alittle higher level of mathematical abstrac-tion helps, he says. When I go to neuro-science meetings,most people do not thinkof me as a physicist, they think of me as acomputational neuroscientist.

The route from physics to neuroscience isnow easier, thanks to the advent of dedi-cated postgraduate programmes that helptheorists catch up with biological know-ledge, Hertz says. Many recent recruits tothe field have been attracted by the noveltyof neuroscience, he says. Everybody is in-

terested in how our brain works. Physicistsare discovering that now you can study it ina useful way.

Li urges physicists to take advantage oftodays welcoming climate in neuroscience,having battled for acceptance herself.There is a growing community of peoplelike myself, but, of course, I would like tosee more, she says.We are the generationthat has to make a difference. We have tomake some kind of a breakthrough to de-monstrate that theoretical neuroscience ishaving an impact and attracting new stu-dents,and become an established disciplinerather than bordering on the boundaries of

other departments.

Physicists help to decode the brainAn increasing number of physicists are using their expertise to understand the human brain.

Paula Gould spoke to several researchers who have made the move to neuroscience

p h y s i c s w e b . o r g

Smart stuff physicists are using techniques such

as MRI to make detailed studies of the brain.

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