Optogenetics: Using Light to Control Your Brain


[♪♩INTRO] Imagine being able to remote control your
cat. By clicking a remote at a receiver on your
beloved kitty’s head, you could make it walk, turn in circles, or even stop moving
altogether. Maybe, with the press of a button, you could
even put it to sleep or turn off its sense of pain when it hurt itself. And even weirder, what if you could control
your own body that way? Well, there’s a scientific technique that
might someday deliver just that. It’s called optogenetics, and it’s a method
for controlling the function of cells using light. Even though it sounds a lot like mind control,
optogenetics is really most useful for learning what specific cells do, or for treating certain
conditions. It does this by using light to control certain
pathways on a cell’s surface called ion channel receptors. These are sort of like switches that start
and stop electrical signals traveling down your cells. Normally, they’re activated when molecules
like neurotransmitters attach themselves to the receptor. That causes charged atoms, or ions, to move
into the cell, which generates an electrical current that can make other cells stop or
start firing. These channels are ultimately what makes your
body move and function. Optogenetics works by using light to control
this process instead of molecules like neurotransmitters. Using fiber optic wires, scientists can transmit
precise light pulses that last just one thousandth of a second directly to a small group of cells. And that triggers ion channels to open and
start sending signals. Now, even before this method, researchers
had actually been trying to control ion channels for years, since that could help us figure
out how cells work or even treat some diseases. But other methods, like drugs or electrodes,
tend to be too slow or imprecise. To really study a small number of neurons,
researchers needed fast, accurate signals. And that’s where optogenetics shined a light
on the problem… literally. It all works thanks to special proteins called
opsins, which are naturally found in organisms like microbes or green algae. When they’re exposed to certain particles
of light, they’ll generate an electrical signal and open a cell’s ion channels. We’ve actually known this about opsins since
the 1970s, when researchers noticed that one in certain bacteria, called bacteriorhodopsin,
opened its ion channels in response to green light. And today, we know about plenty of others,
which start and stop firing neurons in response to all kinds of light. But no matter how many opsins we found, it
took until the beginning of the twenty-first century for scientists to really understand
the applications of them. They realized that, if they could somehow
get these opsins into animal cells, they’d be able to control the ion channels in the
fast, accurate way they needed. And in 2005, they did it for the first time. In the journal Nature Neuroscience, researchers
announced that they’d introduced opsins into a rat’s brain cell — although the
cell was in a petri dish and not a live animal. When they shone blue light on it, it showed
a spike in electrical activity. Essentially, they had made a light sensitive
brain cell! But trying this on live mammals was a lot
harder, because smuggling opsins into a living cell is a tricky business. To do it, researchers had to develop a special
virus that could transfer the protein onto the surface of an animal’s cells — without
the virus itself running haywire. Then, if that worked, they could just insert
a wire into the animal’s brain and use an LED or laser to start manipulating neurons. And they did it! In 2007, scientists demonstrated this technique
for the first time in a live animal, by applying optogenetics to cells in the motor cortex
of a mouse. By transmitting blue light down the optical
fiber in the mouse’ brain, they could make the mouse walk in circles and make it stop
when they turned off the light. Pretty weird. Many other studies also use optogenetics to
study how cell activity correlates with behavior and bodily function. For example, in one study from the journal
Nature, the researchers manipulated cells that put fruit flies to sleep, then could
wake them up on command. Those same cells are involved in the fruit
fly’s internal sleep clock, which has similarities to the one in humans. In mice, researchers have also used optogenetics
to study behavior related to hunger, which could help us model obesity in people. It even has a role in helping us understand
— and maybe someday treat — certain diseases. Like, back in 2011, in the journal Molecular
Therapy, researchers claimed they’d used optogenetics to restore light sensitivity
to cells in a mouse that had lost its vision. That could someday help develop human treatments
for a disease called retinitis pigmentosa, which destroys light sensitive cells in the
retina and causes blindness. And another study, from the journal Neuron,
pinned down specific mice neurons involved with motor control. In humans, cells in a similar part of the
brain are affected by Parkinson’s disease. Now, even though mice, rats, and fruit flies
have brain structures with some features in common with humans, our brains are way more
complicated to understand. We’ll need a lot more work before we’re
ready to give everyone remote controls for their brains. Still, it’s possible that, some day, tiny
optogenetic devices will be working away in our bodies, offering targeted therapies and
cyborg-style nerve implants. We’re definitely there yet. But if it ever happens, just be careful not
to leave the controls to your body lying around the house. If your cat sits on it, it might end up controlling
you instead. Although, really, I guess that’s not much
different from owning a cat today anyways. Thanks for watching this episode of SciShow,
brought to you by our awesome patrons on Patreon! If you want to help us keep making episodes
like this one, you can go to patreon.com/scishow. [♪♩OUTRO]

100 thoughts on “Optogenetics: Using Light to Control Your Brain

  1. How is it everyone just bypasses the animal cruelty involved in these experiments? Where are our ethics?

  2. This would be interesting if there is a way to use optogenetics to stop PTSD and anxiety attacks. Perhaps even to calm down or chill out people with anger issues or with mental trauma or brain damage. Maybe even if people with a tendency for anxious-sensitivity or PTSD could have the option to stop recent events from forming memories–say if they experienced something unsettling or uncomfortable for themselves they could just prevent the past few hours from forming long term memories. Though, limit that to people who need it so we don't run the risk of people causing large scale amnesia hollywood style.

    But Heck! I'd pay good money if someone could make a quick "focus" button for my brain. Though I've got to wonder what the repeated effects of optogenetics are? I'd use that button a lot. Also, I'd like to be able to put myself to sleep with the push of a button…I actually would really like that a lot…

  3. Imagine a dystopian future where a virus with opsin bacteria was released by North Korea and spread globally. NK then controlled the worlds population with lasers from satellites.

    🤟🏻

  4. I would really love to be able to fall asleep at the touch of a button and I don't even suffer from insomnia. I wonder how much the surgery would cost and what would be the side effects. Is the time we spend falling asleep as important as the time we sleep?

  5. Controlling a cat with light is something that I've done once before. But it only works once. BTW a 4 Watt laser will punch a 1 mm hole right through kitty.

  6. The funny thing is that most man made motors are based on wheels or expanding pistons. Whereas the organic motor is often based on contractions.

  7. Researchers, please hook up your fiber optics and such so that I can push a button and go to sleep, and not wake up until it's time to wake up, or until I am on fire or being slapped awake.

  8. I’m curious if this caused distress in the rat. Not the procedure because obviously it would. I’m curious if the rat was distressed by circling without planning to

  9. related but not really, can you make a video about how or why birds develop different color patterns in their feathers?

  10. “My gift to industry is the genetically engineered worker, or Genejack. Specially designed for labor, the Genejack’s muscles and nerves are ideal for his task, and the cerebral cortex has been atrophied so that he can desire nothing except to perform his duties. Tyranny, you say? How can you tyrannize someone who cannot feel pain?”
    -Chairman Sheng-ji Yang

  11. So, can we use this to tell cancer cells to stop dividing? If so, would this be a good way to treat cancer? Not eradicate it. But, rather, just stop it in its tracks.

  12. What of the 2016 MIT study by Li-Huei Tsai [et al.], which demonstrated that 40hz light pulses through the optic nerve seem to induce the 'maintenance state' (gamma oscillations that stimulate the microglia) by which the brain cleans up the β-ameloid plaques that are the prime suspect for Alzheimer's? oR, did you just leave it out because it's the study that made most people aware of the field of optigenetics in the first place?…

  13. great video! the only thing is, when you mention articles instead of saying which journal they came from you could say the author et al. was, would be super helpful to check them quickly + just more informative I think. Great work though!

  14. I wonder if we could get high this way. It'd be great to "Do drugs" that way, rather than doing literal drugs.

  15. Savulescu & Persson (2012) discuss the benefits of universal optogenetic implants used by a superintelligent AI to prevent evil behavior in "Moral enhancement, freedom, and the God Machine":

    "The Great Moral Project was completed in 2045. This involved construction of the most powerful, self-learning, self-developing bioquantum computer ever constructed called the God Machine. The God Machine would monitor the thoughts, beliefs, desires and intentions of every human being. It was capable of modifying these within nanoseconds, without the conscious recognition by any human subjects.

    The God Machine was designed to give human beings near complete freedom. It only ever intervened in human action to prevent great harm, injustice or other deeply immoral behaviour from occurring. For example, murder of innocent people no longer occurred. As soon as a person formed the intention to murder, and it became inevitable that this person would act to kill, the God Machine would intervene. The would-be murderer would ‘change his mind.’ The God Machine would not intervene in trivial immoral acts, like minor instances of lying or cheating. It was only when a threshold insult to some sentient being’s interests was crossed would the God Machine exercise its almighty power." doi.org/10.5840/monist201295321

    Fun stuff.

    We are living in interesting times.

  16. I wonder if it would ever be possible to use Optogenetics to stimulate certain synapses and boost intelligence and executive function, for example improving memory, processing and calculation ability.

  17. Imagine a future where you could control your brain and likely even your body down to the cellular level with say nanotech and metamaterials performing optogenetics at your brain.

  18. I am so sick of you people lying to us. And always selling us our chains in hype so we'll pay for the privilege of putting them on

  19. I am definitely not the target audience of this video. The future applications used as comic relief made me butthurt, complexly.

  20. People are so naive . ANYTHING that can be used for good is WEAPONIZED BY THE MILITARY and used for bad. Think controlling a small child to carry a bomb in to a government building and making that child detonate the bomb on command. Because that's what is going to happen.

  21. So ,is this why they building 5g antenas around us???
    Great, we gona becomes "walking dead"….zombiessss
    And waht is about this "free shots" like "flue shots"…..nothing us free in USA 🙂

  22. Yay biological control, soon the NWO will control all of humanity. Thanks for tip soy boy. Terrible shirt btw. Looks horrible. Fkn weird even.

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