Opto-what? Opto-who? Optogenetics sounds like that scary elective course that you and your friends are trying to avoid to take while at the university. But it is not as bad as you think. With a little bit of creative thinking and a few science fiction parallels, you will quickly understand why Optogenetics is one of the most exciting areas of science and medicine.
On the surface, Optogenetics could allow humans to use a remote control to control our brains. How? By using light. Through this "light controller," you could press a button to put yourself to sleep instantly. If you get injured, you could turn off the pain receptors in your brain with the push of another button on the controller. Or use your controller to control the different motor functions of your body.
The scientific technique could bring us into a future where all of this is possible. This novel way of "mind-control" could be used to treat aging-related brain conditions such as Alzheimer's or Parkinson's disease. It could be used to treat blindness, treat heart abnormalities, and even psychiatric diseases; promises that parallel some of the same claims of Elon Musk's Neuralink project.
Optogenetics is not some far off idea on the fringes of science. It is an idea rooted in science fiction that seems to be attainable according to recent breakthrough research. It is already being used by clinicians and researchers around the world to study the human brain.
Progress in this novel field of neurobiology and engineering has helped researchers decipher brain signals that lead to pain, better understand the neural code for addiction, restore sight in blind mice, reprogram memories, and create new ones. If we can make it past its current limitations and continue on the path that we are currently on, the neurotechnology set in place to bring Optogenetics to the forefront of science could change the world in the coming years. But, we are getting ahead of ourselves.
What is Optogenetics?
Let's go over it one more time. Optogenetics is the science of using light to control the behavior of cells. At the moment, it is one of the most rapidly growing fields of applied research. The most exciting aspect of the technology promises to let us use different frequencies to control the brain.
The cells in question, are neurons in this case. Shelly Fan of Singularity Hub describes it as "A brilliant mind-meld of basic neurobiology and engineering that hijacks the mechanism behind how neurons naturally activate—or are silenced—in the brain." This applied science is being used in laboratories worldwide, helping us discover new exciting things about our minds.
"Optogenetics is the combination of genetics and optics to control well-defined events within specific cells of living tissue. It includes the discovery and insertion into cells of genes that confer light responsiveness", says Scientific American.
"It also includes the associated technologies for delivering light deep into organisms as complex as freely moving mammals, for targeting light-sensitivity to cells of interest, and for assessing specific readouts, or effects, of this optical control."
You need to understand neurons first
Neurons are the fundamental units of the brain and nervous system. They are the cells responsible for receiving sensory input from the world around us, sending motor commands to our muscles when we are on the go, and transforming and relaying the electrical signals at every step in between. These brain cells are living storage containers with "doorways" called ion channels.
These doorways separate the cells from their internal environment acting as a barrier from the outside. If a neuron receives a strong enough input, the cells open their "doors," creating an electrical current that branches out to its other neighboring neurons, communicating information. This is how neurons communicate and how these networks create memories, emotions, and behaviors. Optogenetics hijacks that process.
How do we control these neurons? Opsins are the first part of the formula.
Researchers are not just shining a light on cells and hoping for the best. First, the neurons need to be "redesigned" to be sensitive to light using genetic engineering—the process in which scientists change the information in the genetic code of a living thing. With respect to Optogenetics, scientists take the genetic code of the neurons they want to look at and add a new piece of code to it.
When this new code is added to the subject's neurons, it creates special proteins called opsins. Depending on the opsin used to modify the neuron, it will transmit a nerve impulse when illuminated. Entire organs, body parts, and behaviors could potentially be controlled using this method.
The key to unlocking Optogenetics's power lies in genetic engineering
Opsins are naturally occurring; first discovered in algae, which use these proteins to help themselves move towards the light. The genes for opsins are commonly added to mice in research labs. To do this, scientists use viruses to carefully insert the genetic code of the opsin into the genetic code for the neurons in the mouse.
Still with us? If done correctly, every neuron in the mouse will have the opsin. Since we already have extensive knowledge of the mouse's genetic code, we can choose where to put the opsin. We can put our code into a specific type of neuron or within a particular part of the brain. This allows us to manipulate precisely which neurons we want to control.
One of the most popular opsins is found in green algae. Dubbed channelrhodopsin-2 or ChR2, this opsin is activated by blue light, meaning that it only works when blue light shines on it, and it doesn't respond to other types of light. When you add channelrhodopsin-2 to neurons, blue light acts as a switch turning the neurons on. Even after all of this, we are still only halfway there.
Optical fibers are the second half of our formula for now
Now that our opsins are fully part of our brain or our mice brains, researchers now need to install optical fibers near our opsin neurons to deliver the light stimuli correctly. As mentioned above, depending on the opsins used in conjunction with the light frequency, particular brain regions can be controlled, giving you light-sensitive telepathic superpowers if you are into that type of thing. A more mature form of Optogenetics could open the doors to a powerful clinical therapy that could be used to help people with neurological problems. However, there is a problem.
For this to truly work practically, we are going to need to get rid of those wires poking out of the brain. This would require surgery. No one wants wires or a device poking out of their brain. The next evolution in Optogenetics could be wireless. In a recent study, researchers were able to get neurons to react to light without optical fibers. The Stanford University team has found a way to bioengineer neurons sensitive to light diffused by the skull, offering even faster time than its predecessors. Nonetheless, it is still the first step among many towards wireless brain control.
Optogenetics could change everything
Scientists are looking to treat diseases or even alleviate symptoms using Optogenetics. A simple optogenetic upgrade to your heart could be used to correct heart rate irregularities. Optogenetics could arguably help restore motor function in patients with paralysis by using "light treatments" to trigger muscle contractions.
"There is no doubt that Optogenetics could eventually be used to repair failing organs in the human body. And gene therapy will enable us to do this completely noninvasively," says Vitaly Shevchenko of the MIPT Laboratory for Advanced Studies of Membrane Proteins. "If desired, it would even be possible to 'upgrade' our bodies by replacing some of their parts with more effective components!"
Clinical treatments could be used to help treat neurological generative diseases and even mental health problems. The list goes on. Nonetheless, it is important to mention that we still have a long way to go to do all this. There have been impressive leaps in Optogenetics. But don't forget application of this is not on the fringes of science.
If this does not work, we could always try Elon Musk's Neuralink.