On September 1, 2015, Dr. Stephan
Steidl presented a set of techniques called optogenetic to the Loyola
University students in Neuroscience 300 Seminar. At Loyola, Dr. Steidl works in
the psychology department and is involved with research regarding optogentics.
Optogenetic is a technique that allows researchers to controls the excitation,
inhibition, or signaling pathways of specific cells in neurons with the use of
light (Mohammadi). During the seminar, he explained the importance of
optogenetic and how it impacts his research with the dopamine system. The
seminar allowed a better understanding of the function and properties of
dopamine itself. According to his lecture, Mesolimbic and mesocortical dopamine
pathways controls the dopamine system in the rat brain. The experiment results
demonstrate that dopamine neurons respond to environmental cues that predict
reward and can be classically conditioned. The role of optogenetic in his
research is to be a tool that allows selective targeting of mesopongind inputs
to the VTA. The input that allows the cation channels, ChR2, to open is light. Overall,
optogenetic provides a way to access and control the actions of the circuits in
the brain. For example, in Dr. Steidl’s research, optogenetic has allowed
possible pathways that may control cocaine dependency in the nucleus of rats.
The role and function of optogentics in Dr. Steidl’s lab demonstrates the power
of optogenetic and its impact on possible future discoveries.
The powerful method of optogenetic
is being used everyday in neuroscience, developmental biology, biophysics and
molecular biology to make new discoveries. In the last few years, optogenetic
has made a huge impact in the medical field. An article by Jeffrey Kluger
entitled “Noninvasive Brain Control is Real- and That’s Good” for Time explains
how optogenetic might offer a quick and painless way to regulate neurological
disorders such as Epilepsy. Since treating neurological disorders is one of the
goals, many scientists are continuously doing research with optogenetic. According
to the article, optogenetic involves “introducing opsins into the brain and
then using light to switch certain neurons on and off, effectively controlling
the behavior of a local region of the brain”(Kluger). In one of the study,
Kluger explains how researchers used this technique to implant false memories
in mice, which caused the mice to think they had experience an electrical shock
in a specific part of their cage. But this method is difficult because in order
to stimulate the opsins so that they would switch the neurons on and off as
desired, it requires a threading a fiber-optic cable into the brain and sending
pulses of light through it (Kluger). Due to this, a better method would need to
be developed if optogenetic were to be used in humans. The article explains how
Ed Boyden, an associate professor of biological engineering and brain and
cognitive sciences at MIT, studied the limitations of most opsins that impact optogenetic.
According to Boyden, one of the
limitation is that most “opsins only respond to green or blue wavelengths,
which are pretty much stopped cold by solid objects like the bone and soft
tissue that makes up the head”(Kluger). Due to this, Boyden and his team
attempted to figure out which light-sensitive bacteria and found two that
produce red-sensitive opsins. Later,
Boyden’s grad student “genetically engineered mutants that produce a bigger
kick when hit with red light” (Kluger). This led to a new discovery because
when engineered opsins were introduced into the brains of laboratory mice, they
were able to shut down or turn on local neural activity with nothing more than
a well-aimed beam of red light on the skull.
 |
| "By selectively inserting opsins—which react to light—into them, neurons can be activated or inactivated for research purposes" |
This was not only a success in Boyden’s
research, but a new opportunity and advancement in the medical field. According
to the article, this will allow optogenetic to treat many neurological
disorders such as Epilepsy. Along with epilepsy, many other disorders such as
Parkinson’s disease, depression, and migraine headaches could be controlled
with the use of transcranial magnetic stimulation (Kluger). Until optogentic can
be applied to humans, there will be constant research done on rats and mice
because the work on them is still leading to new discoveries. Although this
form of treatment on humans is still years away, optogenetic has definitely
opened up endless possibilities that will change the history of the medical
world.
Kluger,Jeffrey."Noninvasive'
Brain Control Exists-and That Should Make You Happy." Time. Time, 30
June 2014. Web. 14 Oct. 2015
Mohammadi,
Michael. "Science Techniques: What Is Optogenetics and Why Is It so
Trendy?" A Science Driven Life. Wordpress, 25 Mar. 2013. Web. 15
Oct. 2015.
Image from: http://www.pnas.org/content/110/41/16287.figures-only
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