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 6:10 PM EST, Mon November 24, 2014
If Obama thinks pushing out Hagel will be seen as the housecleaning many have eyed for his national security process, he'll be disappointed, says David Rothkopf.
updated 8:11 AM EST, Tue November 25, 2014
The decision by the St. Louis County prosecuting attorney to announce the Ferguson grand jury decision at night was dangerous, says Jeff Toobin.
updated 3:57 AM EST, Tue November 25, 2014
China's influence in Latin America is nothing new. Beijing has a voracious appetite for natural resources and deep pockets, says Frida Ghitis.
updated 4:51 PM EST, Mon November 24, 2014
Iranian President Hassan Rouhani speaks during a press conference in the capital Tehran on June 14, 2014.
The decision to extend the deadline for talks over Iran's nuclear program doesn't change Tehran's dubious history on the issue, writes Michael Rubin.
updated 2:25 PM EST, Fri November 21, 2014
Maria Cardona says Republicans should appreciate President Obama's executive action on immigration.
updated 7:44 AM EST, Fri November 21, 2014
Van Jones says the Hunger Games is a more sweeping critique of wealth inequality than Elizabeth Warren's speech.
updated 6:29 PM EST, Thu November 20, 2014
obama immigration
David Gergen: It's deeply troubling to grant legal safe haven to unauthorized immigrants by executive order.
updated 8:34 PM EST, Thu November 20, 2014
Charles Kaiser recalls a four-hour lunch that offered insight into the famed director's genius.
updated 3:12 PM EST, Thu November 20, 2014
The plan by President Obama to provide legal status to millions of undocumented adults living in the U.S. leaves Republicans in a political quandary.
updated 10:13 PM EST, Thu November 20, 2014
Despite criticism from those on the right, Obama's expected immigration plans won't make much difference to deportation numbers, says Ruben Navarette.
updated 8:21 PM EST, Thu November 20, 2014
As new information and accusers against Bill Cosby are brought to light, we are reminded of an unshakable feature of American life: rape culture.
updated 5:56 PM EST, Thu November 20, 2014
When black people protest against police violence in Ferguson, Missouri, they're thought of as a "mob."
updated 3:11 PM EST, Wed November 19, 2014
Lost in much of the coverage of ISIS brutality is how successful the group has been at attracting other groups, says Peter Bergen.
updated 8:45 AM EST, Wed November 19, 2014
Do recent developments mean that full legalization of pot is inevitable? Not necessarily, but one would hope so, says Jeffrey Miron.
updated 8:19 AM EST, Wed November 19, 2014
We don't know what Bill Cosby did or did not do, but these allegations should not be easily dismissed, says Leslie Morgan Steiner.
updated 10:19 AM EST, Wed November 19, 2014
Does Palestinian leader Mahmoud Abbas have the influence to bring stability to Jerusalem?
updated 12:59 PM EST, Wed November 19, 2014
Even though there are far fewer people being stopped, does continued use of "broken windows" strategy mean minorities are still the target of undue police enforcement?
updated 9:58 PM EST, Mon November 17, 2014
The truth is, we ran away from the best progressive persuasion voice in our times because the ghost of our country's original sin still haunts us, writes Cornell Belcher.
updated 4:41 PM EST, Tue November 18, 2014
Children living in the Syrian city of Aleppo watch the sky. Not for signs of winter's approach, although the cold winds are already blowing, but for barrel bombs.
updated 8:21 AM EST, Mon November 17, 2014
We're stuck in a kind of Middle East Bermuda Triangle where messy outcomes are more likely than neat solutions, says Aaron David Miller.
updated 7:16 AM EST, Mon November 17, 2014
In the midst of the fight against Islamist rebels seeking to turn the clock back, a Kurdish region in Syria has approved a law ordering equality for women. Take that, ISIS!
updated 11:07 PM EST, Sun November 16, 2014
Ruben Navarrette says President Obama would be justified in acting on his own to limit deportations
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT