Skip to main content

How to 'take over' a brain

By Leonard Mlodinow, Special to CNN
updated 11:14 AM EST, Mon January 7, 2013
STORY HIGHLIGHTS
  • Leonard Mlodinow: In 2013, "optogenetics" is the technology to watch out for
  • Mlodinow: Imagine being able to turn neurons in a brain on and off from the outside
  • He says optogenetics can be used to gain insights on diseases, mental illnesses
  • Mlodinow: It will change the way we understand ourselves as human beings

Editor's note: Leonard Mlodinow is the author, most recently of, "Subliminal: How Your Unconscious Mind Rules Your Behavior." He teaches at California Institute of Technology.

(CNN) -- The hottest field in science this past decade has been neuroscience. That explosion in research, and our understanding of the human brain, was largely fueled by a new technology called functional magnetic resonance imaging (fMRI) that became widely available in the 1990s. Well look out! Another technology-based neuroscience revolution is in the making, this one perhaps even bigger. The term to watch for in 2013 is "optogenetics." It's not a sexy term, but it is a very sexy technology.

The heritage of optogenetics goes way back to 1979, when Nobel Laureate Francis Crick, co-discoverer of the structure of DNA with James Watson and Rosalind Franklin, suggested that neuroscientists should seek to learn how to take control of specific cells in the brain. Well, that certainly would seem to be an advance with great potential. Imagine being able to turn the neurons in an animal's brain on and off from the outside. Sounds like you'd be turning the creature into a robot, sounds like science fiction. Right?

Well, flash forward thirty-some years, and guess what, optogenetics is a reality! Here's how it works... roughly. An obvious approach would be to stick a tiny electrode into an animal's brain and stimulate the cells using electricity.

Leonard Mlodinow
Leonard Mlodinow

Today we have tiny microelectrodes, but they are still too crude for the job. Crick speculated that light could be the tool to use. That turned out to be true: Optogenetics involves inserting fiber-optics tools into an animal's brain, in order to control the target neurons using pulses of light as a trigger.

Become a fan of CNNOpinion
Stay up to date on the latest opinion, analysis and conversations through social media. Join us at Facebook/CNNOpinion and follow us @CNNOpinion on Twitter. We welcome your ideas and comments.



Learning to shine light on a neuron is not the whole answer, though. In order for the method to work, the neurons have to be re-engineered so that they react to the light. That was made possible by the amazing discovery of a kind of protein that can be used to turn neurons on and off in response to light.

The exotic light-sensitive protein is not present in normal neurons, so scientists designed a way to insert it. That is accomplished through a type of gene engineering called "transfection" that employs "vectors" such as viruses to infect the target neuron, and, once there, to insert genetic material that will cause the neuron to manufacture the light-sensitive protein.

Put it all together, and you have that sci-fi-sounding technology: genetically-engineered neurons that you can turn on and off at will, inside the brain of a living and freely-moving animal.

It is the combined use of optics and genetics that give optogenetics its name, but it's not the "how" that makes optogenetics exciting, it is the "what." Scientists didn't really develop it to "take over" a creature's brain. They developed it, like fMRI, to learn about the brain, and how the brain works, in this case by studying the effect of stimulating specific types of neurons.

2012's space and science milestones

The technology is already beginning to pay off, and despite its recent invention, the word on the street is that a Nobel Prize isn't far off. In one application of optogenetics, scientists investigated how neurons that make dopamine, a neurotransmitter in the brain, may give rise to feelings of reward and pleasure. That work may help scientists understand the pleasure-related pathologies involved in clinical depression.

In another application, scientists selectively stimulated brain cells in animal models of Parkinson's disease, a disease that involves the disruption of information-processing in the brain. That research gave new insight into the circuitry involved in the disease, and the way that the therapies we currently prescribe for it operate. It has also suggested new directions for therapeutic intervention.

Schizophrenia is another disorder that involves information processing issues in the brain. The illusion of hearing voices, for example, may arise from the failure of an internal mechanism for notifying a person when his or her thoughts are "self-generated." Optogenetics has been employed to better understand a kind of brain activity called "gamma oscillations" that appear abnormal in schizophrenia -- and also in autism.

Today, we are a long way from the era when a single person working with an assistant or two can make a revolutionary technological breakthrough. It took, instead, decades of work in many fields, which came together, only very recently, to bring Crick's vision to fruition. But now that it's here, optogenetics is destined to change the way we treat mental illness, and eventually, even, the way we understand ourselves as human beings.

Follow us on Twitter @CNNOpinion

Join us on Facebook/CNNOpinion

The opinions expressed in this commentary are solely those of Leonard Mlodinow.

ADVERTISEMENT
Part of complete coverage on
updated 9:05 AM EDT, Tue September 16, 2014
LZ Granderson says Congress has rebuked the NFL on domestic violence issue, but why not a federal judge?
updated 7:49 AM EDT, Tue September 16, 2014
Mel Robbins says the only person you can legally hit in the United States is a child. That's wrong.
updated 1:23 PM EDT, Mon September 15, 2014
Eric Liu says seeing many friends fight so hard for same-sex marriage rights made him appreciate marriage.
updated 3:38 PM EDT, Mon September 15, 2014
SEATTLE, WA - SEPTEMBER 04: NFL commissioner Roger Goodell walks the sidelines prior to the game between the Seattle Seahawks and the Green Bay Packers at CenturyLink Field on September 4, 2014 in Seattle, Washington. (Photo by Otto Greule Jr/Getty Images)
Martha Pease says the NFL commissioner shouldn't be judge and jury on player wrongdoing.
updated 9:15 AM EDT, Tue September 16, 2014
It's time for a much needed public reckoning over U.S. use of torture, argues Donald P. Gregg.
updated 8:25 AM EDT, Tue September 16, 2014
Peter Bergen says UK officials know the identity of the man who killed U.S. journalists and a British aid worker.
updated 7:28 AM EDT, Tue September 16, 2014
Joe Torre and Esta Soler say much has been achieved since a landmark anti-violence law was passed.
updated 4:55 PM EDT, Fri September 12, 2014
David Wheeler wonders: If Scotland votes to secede, can America take its place and rejoin England?
updated 8:41 AM EDT, Tue September 16, 2014
Jane Stoever: Society must grapple with a culture in which 1 in 3 teen girls and women suffer partner violence.
updated 4:36 PM EDT, Fri September 12, 2014
World-famous physicist Stephen Hawking recently said the world as we know it could be obliterated instantaneously. Meg Urry says fear not.
updated 6:11 PM EDT, Fri September 12, 2014
Bill Clinton's speech accepting the Democratic nomination for president in 1992 went through 22 drafts. But he always insisted on including a call to service.
updated 6:18 PM EDT, Fri September 12, 2014
Joe Amon asks: What turns a few cases of disease into thousands?
updated 1:21 PM EDT, Thu September 11, 2014
Sally Kohn says bombing ISIS will worsen instability in Iraq and strengthen radical ideology in terrorist groups.
updated 6:31 PM EDT, Tue September 16, 2014
Analysts weigh in on the president's plans for addressing the threat posed by the Islamic State of Iraq and Syria.
updated 9:27 AM EDT, Thu September 11, 2014
Artist Prune Nourry's project reinterprets the terracotta warriors in an exhibition about gender preference in China.
updated 9:36 AM EDT, Wed September 10, 2014
The Apple Watch is on its way. Jeff Yang asks: Are we ready to embrace wearables technology at last?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT