Issue 1 Spring 2022

Written By: Cindy DeDianous | Designed By: Cindy DeDianous
Mind control is real! With the flick of a switch, we have
the power to turn the brain on and off. Cutting off your
sense of smell, restoring blindness, reactivating lost
memories—they’re all within the realm of possibility. No,
this isn’t the plot synopsis for a dystopian sci-fi movie.
With a technique known as optogenetics, scientists are
now doing the impossible.
In 2005, researchers at Stanford University capitalized on
this connection. Using a virus, they altered the genetic code of
a group of neurons to give them the ability to produce opsins.
When a specific wavelength of light was shone on the brain,
only the neurons that had been genetically modified to be lightresponsive
were activated or inhibited. This specificity is the
key to optogenetics. Instead of activating entire cell
populations, researchers could now target certain neurons or
brain circuits and definitively link resulting changes in animal
behavior to the cells' function.
Having a bad day? Think about your happiest memory. Did
that improve your mood? According to researchers at MIT, one
day, it might. They exposed mice to a pleasurable experience
and used a light-sensitive protein to label the cells in the
hippocampus that were storing the positive memory. The mice
were then exposed to high-stress situations, prompting
depression-like symptoms. A fiber-optic cable that emitted blue
light was implanted into the mice's heads. When optogenetics
was used to activate the positive memory, the mice temporarily
experienced a drastic change in mood and behaved like mice
who had never experienced depression!
The secret behind this technology can be found right in
Scarsdale’s backyard: green algae. Photosynthetic
organisms like algae use specialized proteins, called
opsins, to locate areas with optimal light conditions for
photosynthesis. When activated by light, opsins open
channels in the cell membrane. As ions flow across, they
generate a change in charge that alerts the algae to move
toward the light. Remind you of anything? This movement
of ions is similar to the process of depolarization, which
causes neurons to fire.
Optogenetic ‘mind control’ is closer to reaching
humans than you might think. Researchers at Sorbonne
Université recently used a combination of optogenetics
and tech-savvy goggles to return some characteristics
of sight to a blind patient. When the goggles sense
shifts in light intensity, they project the corresponding
light pulses onto the retina optogenetically stimulate
retinal ganglion cells, which play a vital role in image
processing. The results were astounding: the patient
was able to locate and count different objects!
Optogenetics almost seems too good to be true. But
don’t worry, it’s not being used to brainwash me or you
(yet). Instead, it’s prompting breakthrough after
breakthrough and shedding light on the deepest secrets
of our brain.
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