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 4:06 PM EDT, Tue October 21, 2014
Timothy Stanley says Lewinsky is shamelessly playing the victim in her affair with Bill Clinton, humiliating Hillary Clinton again and aiding her critics
updated 10:14 AM EDT, Thu October 23, 2014
Imagine being rescued from modern slavery, only to be charged with a crime, writes John Sutter
updated 12:00 PM EDT, Tue October 21, 2014
Tidal flooding used to be a relatively rare occurrence along the East Coast. Not anymore, write Melanie Fitzpatrick and Erika Spanger-Siegfried.
updated 7:35 AM EDT, Tue October 21, 2014
Carol Costello says activists, writers, politicians have begun discussing their abortions. But will that new approach make a difference on an old battleground?
updated 9:12 AM EDT, Tue October 21, 2014
Sigrid Fry-Revere says the National Organ Transplant Act has caused more Americans to die waiting for an organ than died in both World Wars, Korea, Vietnam, Afghanistan and Iraq
updated 2:51 PM EDT, Tue October 21, 2014
Crystal Wright says racist remarks like those made by black Republican actress Stacey Dash do nothing to get blacks to join the GOP
updated 6:07 PM EDT, Tue October 21, 2014
Mel Robbins says by telling her story, Monica Lewinsky offers a lesson in confronting humiliating mistakes while keeping her head held high
updated 9:29 AM EDT, Mon October 20, 2014
Cornell Belcher says the story of the "tea party wave" in 2010 was bogus; it was an election determined by ebbing Democratic turnout
updated 4:12 PM EDT, Mon October 20, 2014
Les Abend says pilots want protocols, preparation and checklists for all contingencies; at the moment, controlling a deadly disease is out of their comfort zone
updated 11:36 PM EDT, Sun October 19, 2014
David Weinberger says an online controversy that snowballed from a misogynist attack by gamers into a culture war is a preview of the way news is handled in a world of hashtag-fueled scandal
updated 8:23 AM EDT, Mon October 20, 2014
Julian Zelizer says Paul Krugman makes some good points in his defense of President Obama but is premature in calling him one of the most successful presidents.
updated 10:21 PM EDT, Sun October 19, 2014
Conservatives can't bash and slash government and then suddenly act surprised if government isn't there when we need it, writes Sally Kohn
updated 8:05 AM EDT, Wed October 22, 2014
ISIS is looking to take over a good chunk of the Middle East -- if not the entire Muslim world, write Peter Bergen and Emily Schneider.
updated 9:00 AM EDT, Mon October 20, 2014
The world's response to Ebola is its own sort of tragedy, writes John Sutter
updated 4:33 PM EDT, Fri October 17, 2014
Hidden away in Russian orphanages are thousands of children with disabilities who aren't orphans, whose harmful treatment has long been hidden from public view, writes Andrea Mazzarino
updated 1:22 PM EDT, Sat October 18, 2014
When you hear "trick or treat" this year, think "nudge," writes John Bare
updated 12:42 AM EDT, Sat October 18, 2014
The more than 200 kidnapped Nigerian schoolgirls have become pawns in a larger drama, writes Richard Joseph.
updated 9:45 AM EDT, Fri October 17, 2014
Peggy Drexler said Amal Alamuddin was accused of buying into the patriarchy when she changed her name to Clooney. But that was her choice.
updated 4:43 PM EDT, Thu October 16, 2014
Ford Vox says the CDC's Thomas Frieden is a good man with a stellar resume who has shown he lacks the unique talents and vision needed to confront the Ebola crisis
updated 4:58 AM EDT, Sat October 18, 2014
How can such a numerically small force as ISIS take control of vast swathes of Syria and Iraq?
updated 9:42 AM EDT, Fri October 17, 2014
How big a threat do foreign fighters in Syria and Iraq pose to the West? It's a question that has been much on the mind of policymakers and commentators.
updated 8:21 AM EDT, Fri October 17, 2014
More than a quarter-million American women served honorably in the Iraq and Afghanistan wars. Now they are home, we have an obligation to help them transition back to civilian life.
updated 4:27 PM EDT, Thu October 16, 2014
Paul Begala says Rick Scott's deeply weird refusal to begin a debate because rival Charlie Crist had a fan under his podium spells disaster for the Florida governor--delighting Crist
updated 12:07 AM EDT, Thu October 16, 2014
The longer we wait to engage on Ebola, the more limited our options will become, says Marco Rubio.
updated 7:53 AM EDT, Wed October 15, 2014
Democratic candidates who run from President Obama in red states where he is unpopular are making a big mistake, says Donna Brazile
updated 12:29 AM EDT, Thu October 16, 2014
At some 7 billion people, the world can sometimes seem like a crowded place. But if the latest estimates are to be believed, then in less than a century it is going to feel even more so -- about 50% more crowded, says Evan Fraser
updated 12:53 PM EDT, Mon October 20, 2014
Paul Callan says the Ebola situation is pointing up the need for better leadership
updated 6:45 PM EDT, Wed October 15, 2014
Nurses are the unsung heroes of the Ebola outbreak. Yet, there are troubling signs we're failing them, says John Sutter
updated 1:00 PM EDT, Wed October 15, 2014
Dean Obeidallah says it's a mistake to give up a business name you've invested energy in, just because of a new terrorist group
updated 7:01 PM EDT, Wed October 15, 2014
Fear of Ebola is contagious, writes Mel Robbins; but it's time to put the disease in perspective
updated 1:44 PM EDT, Tue October 14, 2014
Oliver Kershaw says that if Big Tobacco is given monopoly of e-cigarette products, public health will suffer.
updated 9:35 AM EDT, Sat October 18, 2014
Stop thinking your job will make you happy.
updated 10:08 PM EDT, Tue October 14, 2014
Ruben Navarrette says it's time to deal with another scandal involving the Secret Service — one that leads directly into the White House.
updated 7:25 AM EDT, Tue October 14, 2014
Americans who choose to fight for militant groups or support them are young and likely to be active in jihadist social media, says Peter Bergen
updated 9:03 AM EDT, Mon October 13, 2014
Stephanie Coontz says 11 years ago only one state allowed same sex marriage. Soon, some 60% of Americans will live where gays can marry. How did attitudes change so quickly?
updated 4:04 PM EDT, Tue October 14, 2014
Legalizing assisted suicide seems acceptable when focusing on individuals. But such laws would put many at risk of immense harm, writes Marilyn Golden.
updated 9:07 AM EDT, Mon October 13, 2014
Julian Zelizer says the issues are huge, but both parties are wrestling with problems that alienate voters
updated 6:50 PM EDT, Mon October 13, 2014
Mel Robbins says the town's school chief was right to cancel the season, but that's just the beginning of what needs to be done
updated 11:43 AM EDT, Sat October 11, 2014
He didn't discover that the world was round, David Perry writes. So what did he do?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT