Optogenetics technology will restore blindness

Are optogenetics helpful to treat vision disorders in human?

Researchers at the University of Southern California (USC) used technology that is developed by using optogenetics to restore visual behavior in mice, which holds promise for treating human blindness. Optogenetics is new technology of using association of optics and genetics to control neuron activity.
The main purpose of my blog is to instruct audience about new scientific method optogenetics and explain the effectiveness of the method in biology as it has potential role in medicine, namely my area of study.
According to Ed Boyden, a professor at the MIT Media Lab, the research on mice by using the new study opens new frames to get visual information that might correct human sight in the future.
Some people suffer from damaging light-sensitive cells in the retina, which leads to a serious disease, retinius pigmentosa. Mostly the cause of eyesight diseases is genetic mutations, which leads to damaging of light sensitive cells of the retina called photoreceptors. There are two types of photopeceptors: rods and cones. The function of rods and cones is to convert light into electrical signals by bipolar cells of the retina. Optogenetics allows to repair destroyed cells of the retina.
The new technology involves addition genes that code proteins called channelrhodopsins, which are present  in the photoreceptors. Light-sensitive proteins are activated by channels which control the flow of ions (charged molecules) in order to stimulate the electrical activity of the cell.

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The researchers decided to set a target on bipolar cells called ON cells. In fact, ON cells are activated in light in order to express the channelrhodopsin gene including DNA sequence, whereas OFF bipolar cells are restricted in bright light.
Turning to the experimental part, the experiment was performed on the blind mice, which have some genetic mutations including the absence of photoreceptor cells and on sighted mice as a control. At the beginning of the experiment, some blind mice were injected by the virus containing the channelrhodopsin gene and others were not. The gene was accurately inserted to the ON bipolar cells. Then they are observed the ability of mice to see objects by letting them go through a maze in order to test their vision. During the experiment, normal (sighted) mice were able to easily navigate through the maze, whereas blind mice, untreated ones have some difficulties. At the first time treated mice and untreated ones had similar activity functions. However after two weeks the researchers found out unusual thing, blind (treated) mice were able to navigate the maze as well as the sighted mice.
Sheila Nirenberg, associate professor of physiology at Weill Medical College of Cornell University states that according to the study mice had some vision restored, as a result of successfully expressed gene activity in ON cells and there were no side effects.

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The treatment is expected to be developed for medical purposes to human patients.
Nowadays many research groups are still working on  the usage of optogenetics method to treat sight disorders in people.
However it is believed that optogenetics, an unknown test for human could be used to restore human blindness  in the near future.

Reference

Anne Trafton, 2011. "MIT News Office" Last modified April 20, 2011.
http://newsoffice.mit.edu/2011/blindness-boyden-0420
http://transhumanismwr10206.weebly.com/optogenetic-therapy.html
http://transhumanismwr10206.weebly.com/optogenetic-therapy.html