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 12:50 PM EDT, Tue July 29, 2014
LZ Granderson says the cyber-standing ovation given to Robyn Lawley, an Australian plus-size model who posted unretouched photos, shows how crazy Americans' notions of beauty have become
updated 7:56 AM EDT, Mon July 28, 2014
A crisis like the Gaza conflict or the surge of immigrants can be an opportunity for a lame duck president, writes Julian Zelizer
updated 2:22 PM EDT, Sat July 26, 2014
Carol Costello says the league's light punishment sent the message that it didn't consider domestic violence a serious offense
updated 8:51 AM EDT, Mon July 28, 2014
Danny Cevallos says saggy pants aren't the kind of fashion statement protected by the First Amendment.
updated 2:52 PM EDT, Mon July 28, 2014
Margaret Hoover says some GOP legislators support a state's right to allow same-sex marriage and the right of churches, synagogues and mosques not to perform the sacrament
updated 2:31 PM EDT, Mon July 28, 2014
Megan McCracken and Jennifer Moreno say it's unacceptable for states to experiment with new execution procedures without full disclosure
updated 2:50 PM EDT, Mon July 28, 2014
Priya Satia says today's drones for bombardment and surveillance have their roots in the deadly history of Western aerial control of the Middle East that began in World War One
updated 12:35 PM EDT, Mon July 28, 2014
Jeff Yang says it's great to see the comics make an effort at diversifying the halls of justice
updated 11:55 AM EDT, Sat July 26, 2014
Rick Francona says the reported artillery firing from Russian territory is a sign Vladimir Putin has escalated the Ukraine battle
updated 2:22 PM EDT, Sun July 27, 2014
Paul Callan says the fact that appeals delay the death penalty doesn't make it an unconstitutional punishment, as one judge ruled
updated 6:25 PM EDT, Thu July 24, 2014
Pilot Robert Mark says it's been tough for the airline industry after the plane crashes in Ukraine and Taiwan.
updated 11:10 AM EDT, Fri July 25, 2014
Jennifer DeVoe laments efforts to end subsidies that allow working Americans to finally afford health insurance.
updated 11:33 AM EDT, Sat July 26, 2014
Ruti Teitel says assigning a costly and humiliating "collective guilt" to Germany after WWI would end up teaching the global community hard lessons about who to blame for war crimes
updated 8:45 AM EDT, Fri July 25, 2014
John Sutter responds to criticism of his column on the ethics of eating dog.
updated 9:02 AM EDT, Fri July 25, 2014
Frida Ghitis says it's tempting to ignore North Korea's antics as bluster but the cruel regime is dangerous.
updated 2:50 PM EDT, Fri July 25, 2014
To the question "Is Putin evil?" Alexander Motyl says he is evil enough for condemnation by people of good will.
updated 2:03 PM EDT, Thu July 24, 2014
Laurie Garrett: Poor governance, ignorance, hysteria worsen the Ebola epidemic in Sierra Leone, Guinea, Liberia.
updated 9:49 AM EDT, Thu July 24, 2014
Patrick Cronin and Kelley Sayler say the world is seeing nonstate groups such as Ukraine's rebels wielding more power to do harm than ever before
updated 6:05 PM EDT, Wed July 23, 2014
Ukraine ambassador Olexander Motsyk places blame for the MH17 tragedy squarely at the door of Russia
updated 7:42 AM EDT, Thu July 24, 2014
Mark Kramer says Russia and its proxies have a history of shooting down civilian aircraft, often with few repercussions
updated 2:53 PM EDT, Thu July 24, 2014
Les Abend says, with rockets flying over Tel Aviv and missiles shooting down MH17 over Ukraine, a commercial pilot's pre-flight checklist just got much more complicated
updated 9:17 AM EDT, Thu July 24, 2014
Mark Kramer says Russia and its proxies have a history of shooting down civilian aircraft, often with few repercussions
updated 12:37 PM EDT, Thu July 24, 2014
Gerard Jacobs says grieving families and nations need the comfort of traditional rituals to honor the remains of loved ones, particularly in a mass disaster
updated 10:13 AM EDT, Thu July 24, 2014
The idea is difficult to stomach, but John Sutter writes that eating dog is morally equivalent to eating pig, another intelligent animal. If Americans oppose it, they should question their own eating habits as well.
updated 12:30 PM EDT, Wed July 23, 2014
Bill van Esveld says under the laws of war, civilians who do not join in the fight are always to be protected. An International Criminal Court could rule on whether Israeli airstrikes and Hamas rocketing are war crimes.
updated 10:08 AM EDT, Wed July 23, 2014
Gordon Brown says the kidnapped Nigerian girls have been in captivity for 100 days, but the world has not forgotten them.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT