Optogenetics
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What is optogenetics?- Optogenetics is an emerging field of science that combines both optics and genetics (gene therapy) in order to manipulate the activation of light-sensitive genes within the brain. Scientists are able to clone light-sensitive ion channels crucial in regulating gene expression within mammalian cells. Neurons within the human brain may be injected with viral vectors containing many light-sensitive microbial molecules, including ChR2, a light-induced cation channel, and NpHR, a light-induced chloride pump. This allows scientists to control neural functions in maintaining human health, responding to protein deficiency, and study the neurological effects of psychiatric diseases. This therapy specifically targets patients suffering from retinitis pigmentosa, other neurological disorders such as depression or anxiety, as well as advocates for human advancement.
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Optogenetic Therapy in Human Technological AdvancemenT
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The promotion of optogenetics has been ongoing through the introduction of more optical fiber implants and the publication of experimental results on brain stimulation in mice and monkeys. The depolarizing and hyperpolarizing functions of these microbial molecules across neuron membranes allow scientists to propose several approaches to treating mice
with retinitis pigmentosa. Existing currently in pre-clinical stages, optogenetic therapy has been tested on both mice and monkeys, successfully restoring vision in mice who suffer from retinitis pigmentosa, stimulating responsive behavior in monkeys when performing fixed tasks, and simulating the function of biological pacemaker cells. |
Treating Retinitis Pigmentosa Patients USING Optogenetic Therapy
Retinitis pigmentosa, an incurable hereditary disease described by the gradual loss of sight, affects two million people worldwide. Retinitis pigmentosa is characterized by early symptoms of night blindness, eventually causing the degradation of highly sensitive rod photoreceptors. Optogenetics is currently studied as a human advancement method of restoring photosensitivity while not impeding the progression of the disease. Busskamp (2012), a researcher from the Friedrich Miescher Institute for Biomedical Research,attempts to restore photosensitivity within affected mice through creating photosensors and incorporating them into existing retinal circuitry (p. 169). These light sensors are able to make retinal cells light-responsive, thus converting them into artificial photoreceptors. Through control of retinal activity, it would be possible then to mimic the activity of retinal circuits.
The target population for optogenetic studies was legally blind patients to eliminate the risk of having detrimental effects on the central retinal system still functional in patients who have the disease. Upon treatment of mice suffering from retinitis pigmentos using optogenetic methods, the mice exhibited ON responses in retinal ganglion cells and slight potentials within the cortex corresponding to visual images, thereby changing the mice behavior and activity due to location. “The retinas of these transgenic animals regained light sensitivity and the rats showed visually guided behavior.” (Busskamp, 2012) Upon treatment of mice using viral vectors containing NpHR, the mice have also demonstrated behaviors corresponding to OFF cells at a decrease of light intensity. Successful therapy for retinitis pigmentosa optogenetically currently exists in the pre-clinical trial stage.
The target population for optogenetic studies was legally blind patients to eliminate the risk of having detrimental effects on the central retinal system still functional in patients who have the disease. Upon treatment of mice suffering from retinitis pigmentos using optogenetic methods, the mice exhibited ON responses in retinal ganglion cells and slight potentials within the cortex corresponding to visual images, thereby changing the mice behavior and activity due to location. “The retinas of these transgenic animals regained light sensitivity and the rats showed visually guided behavior.” (Busskamp, 2012) Upon treatment of mice using viral vectors containing NpHR, the mice have also demonstrated behaviors corresponding to OFF cells at a decrease of light intensity. Successful therapy for retinitis pigmentosa optogenetically currently exists in the pre-clinical trial stage.
Concerns:
Scientists claim that this new technology will allow them to study random behaviors from randomly generated light patterns.
However, this research field raises concerns about human brain alterations, which some believe are possible and can happen undetected. Although tests are currently being performed on mice, humans have a much greater complexity in gene functions. Light sensitive genes may be left permanently on by these triggers and will leave an unprecedented change in human behavior as a result. As optogenetic technology improves, the need for better fiber-optic tools must increase. There must be newly developed hardware that supports the ability to reflect and transmit light across neurons. The overuse of optogenetics may lead to genetically modified cells that are sensitive to both sunlight and laser light. Existing biophysical and genetic engineering may also hinder any progress in its commercial use.
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References
Busskamp, V., Picaud, S., Sahel, J. A., &Roska, B. (2012).Optogenetic therapy for retinitis pigmentosa. Gene
Therapy, 19(2), 169-75. doi: 10.1038/gt.2011.155
Coghlan, A. (2012), Light-activated brain cells boost monkey skills.New Scientist. Retrieved from:
http://www.newscientist.com/article/dn22114-lightactivated-brain-cells-boost-monkey-skills.html
Jia, Z., Valiunus, V., Lu, Z., et al. (2011). Stimulating Cardiac Muscle by Light: Cardiac Optogenetics by Cell
Delivery.CircArrhythmElectrophysiol, 4(5) 753–760. doi:10.1161/CIRCEP.111.964247
Vanduffel, W., et al. (2012)Optogenetically Induced Behavioral and Functional Network Changes in Primates. Current
Biology, 22 (18) 1722-1726.doi: 10.1016/j.cub.2012.07.023
Images:
http://bbrfoundation.org/sites/bbrf.civicactions.net/files/styles/165px-wide/public/optogenetics.jpg
http://2.bp.blogspot.com/_Y8VhnAd_aEg/TUUkSIZy7CI/AAAAAAAAB4o/Lun6tVeoVe4/s1600/optogenetics.png
http://2.bp.blogspot.com/_Y8VhnAd_aEg/TUUa6SPPNdI/AAAAAAAAB4k/GlVpJatb-MA/s1600/532d9_oct2109eng-optogenetics.jpg
http://www.extremetech.com/wp-content/uploads/2012/01/optogenetics-neuron-640x353.jpg
http://lumencor.com/wp-content/uploads/2011/09/optogenetics.jpg
Video:
http://www.youtube.com/watch?feature=player_embedded&v=I64X7vHSHOE#!
USciences
WRT 102-06
Alexander Ma
Scientists claim that this new technology will allow them to study random behaviors from randomly generated light patterns.
However, this research field raises concerns about human brain alterations, which some believe are possible and can happen undetected. Although tests are currently being performed on mice, humans have a much greater complexity in gene functions. Light sensitive genes may be left permanently on by these triggers and will leave an unprecedented change in human behavior as a result. As optogenetic technology improves, the need for better fiber-optic tools must increase. There must be newly developed hardware that supports the ability to reflect and transmit light across neurons. The overuse of optogenetics may lead to genetically modified cells that are sensitive to both sunlight and laser light. Existing biophysical and genetic engineering may also hinder any progress in its commercial use.
___________________________________________________________________________________________________________________________________________________________________________________
References
Busskamp, V., Picaud, S., Sahel, J. A., &Roska, B. (2012).Optogenetic therapy for retinitis pigmentosa. Gene
Therapy, 19(2), 169-75. doi: 10.1038/gt.2011.155
Coghlan, A. (2012), Light-activated brain cells boost monkey skills.New Scientist. Retrieved from:
http://www.newscientist.com/article/dn22114-lightactivated-brain-cells-boost-monkey-skills.html
Jia, Z., Valiunus, V., Lu, Z., et al. (2011). Stimulating Cardiac Muscle by Light: Cardiac Optogenetics by Cell
Delivery.CircArrhythmElectrophysiol, 4(5) 753–760. doi:10.1161/CIRCEP.111.964247
Vanduffel, W., et al. (2012)Optogenetically Induced Behavioral and Functional Network Changes in Primates. Current
Biology, 22 (18) 1722-1726.doi: 10.1016/j.cub.2012.07.023
Images:
http://bbrfoundation.org/sites/bbrf.civicactions.net/files/styles/165px-wide/public/optogenetics.jpg
http://2.bp.blogspot.com/_Y8VhnAd_aEg/TUUkSIZy7CI/AAAAAAAAB4o/Lun6tVeoVe4/s1600/optogenetics.png
http://2.bp.blogspot.com/_Y8VhnAd_aEg/TUUa6SPPNdI/AAAAAAAAB4k/GlVpJatb-MA/s1600/532d9_oct2109eng-optogenetics.jpg
http://www.extremetech.com/wp-content/uploads/2012/01/optogenetics-neuron-640x353.jpg
http://lumencor.com/wp-content/uploads/2011/09/optogenetics.jpg
Video:
http://www.youtube.com/watch?feature=player_embedded&v=I64X7vHSHOE#!
USciences
WRT 102-06
Alexander Ma