Students at Stanford may have devised a way to activate neurons not with drugs or electricity but with light. In an experiment they placed a small lab rat into a plastic basin. It acted like a normal rat except for the wire strapped to his brain. A switch was flipped and a blue light glowed and the mouse ran in a counter clock wise circle. This showed that the light had some effect on the brain.
Light does not affect the brain naturally. Using algae genes the brain can create proteins that do respond to light. This makes for treatments with pinpoint accuracy compared to drugs and electricity which can affect more parts of the brain than needed.It was discovered by Peter Hegemann that algae proteins move under the effects of light.
Roger Tsien read Hegemann's work and decided to use this for neural cells. He had figured out which genes responeded to light. He did figure it out but never realised it. Then came inserting the gene into neurons. The process in inserting the algae genes into the brain follows:"Insert the gene (plus promoter) into a group of viral particles and inject them into the brain. The viruses infect a cubic millimeter or two of tissue. That is to say, they insert the new gene into every neuron in that area, indiscriminately. But because of the promoter, the gene will only turn on in one type of neuron. All the other neurons will ignore it. Imagine you wanted only the lefty in an outfield to catch. How would you do that? Distribute left-handed gloves to all the players. The righties would just stand there, fidgeting and calling their agents. The lefty would spring into action. Just as the lefty is “tagged” by his ability to use the glove, a neuron is “tagged” by its ability to use the gene. Bye-bye side effects: Researchers would be able to stimulate one kind of neuron at a time." The project was put off. Hegemann found Tsien's work and used the correct gene to prove that light can affect a neuron.
Karl Deisseroth, is a psychiatrist at Stanford who is working on this idea currently along with his grad students,Feng Zhang and Ed Boyden. They had managed to make the neurons fire using blue light but it appeared that the algea genes could only fire and not inhibit the neuron. It was until later that a gene found in bacteria could do the opposite of the algea gene with yellow light.
Though the project is currently still in the works there is a great deal of promise for traements for certain mental conditions. Parkinson's disease is one of the bigger ideas for treating. Not only can the algae genes help manipulate neurons but also help monitor them. By mixing the genes with a florescent that glows when exposed to light doctors can track brain development. This would allow doctors to see and change whatever is needed to make sure the brain stays healthy. This two way treatment would be a great leap in neural medicine. Currently there is only one way treatment. You send the drug out and hope for the best or monitor it and do nothing.
It also has potential in prosthetics. Imagine being able to control a prosthetic arm in the same manner as a normal arm. The brain would be able to send information to the arm to move and be able to recieve feedback from the arm. Currently most prosthetics can only really recieve commands from the brain but usually send nothing back. With the help of light. Certain LEDs could shine in the brain that would give the sensations that go with using a natural limb such a weight, temperature, and texture.
This was a real interesting article. It seems strange to use something such as light to alter the brain but after reading this article it does seem like a good idea. Only time will tell how far this project goes. There a good amount of technological leaps that have to be made to perfect this technology but we can get there one day.
http://www.wired.com/magazine/2009/10/mf_optigenetics/3/
Light does not affect the brain naturally. Using algae genes the brain can create proteins that do respond to light. This makes for treatments with pinpoint accuracy compared to drugs and electricity which can affect more parts of the brain than needed.It was discovered by Peter Hegemann that algae proteins move under the effects of light.
Roger Tsien read Hegemann's work and decided to use this for neural cells. He had figured out which genes responeded to light. He did figure it out but never realised it. Then came inserting the gene into neurons. The process in inserting the algae genes into the brain follows:"Insert the gene (plus promoter) into a group of viral particles and inject them into the brain. The viruses infect a cubic millimeter or two of tissue. That is to say, they insert the new gene into every neuron in that area, indiscriminately. But because of the promoter, the gene will only turn on in one type of neuron. All the other neurons will ignore it. Imagine you wanted only the lefty in an outfield to catch. How would you do that? Distribute left-handed gloves to all the players. The righties would just stand there, fidgeting and calling their agents. The lefty would spring into action. Just as the lefty is “tagged” by his ability to use the glove, a neuron is “tagged” by its ability to use the gene. Bye-bye side effects: Researchers would be able to stimulate one kind of neuron at a time." The project was put off. Hegemann found Tsien's work and used the correct gene to prove that light can affect a neuron.
Karl Deisseroth, is a psychiatrist at Stanford who is working on this idea currently along with his grad students,Feng Zhang and Ed Boyden. They had managed to make the neurons fire using blue light but it appeared that the algea genes could only fire and not inhibit the neuron. It was until later that a gene found in bacteria could do the opposite of the algea gene with yellow light.
Though the project is currently still in the works there is a great deal of promise for traements for certain mental conditions. Parkinson's disease is one of the bigger ideas for treating. Not only can the algae genes help manipulate neurons but also help monitor them. By mixing the genes with a florescent that glows when exposed to light doctors can track brain development. This would allow doctors to see and change whatever is needed to make sure the brain stays healthy. This two way treatment would be a great leap in neural medicine. Currently there is only one way treatment. You send the drug out and hope for the best or monitor it and do nothing.
It also has potential in prosthetics. Imagine being able to control a prosthetic arm in the same manner as a normal arm. The brain would be able to send information to the arm to move and be able to recieve feedback from the arm. Currently most prosthetics can only really recieve commands from the brain but usually send nothing back. With the help of light. Certain LEDs could shine in the brain that would give the sensations that go with using a natural limb such a weight, temperature, and texture.
This was a real interesting article. It seems strange to use something such as light to alter the brain but after reading this article it does seem like a good idea. Only time will tell how far this project goes. There a good amount of technological leaps that have to be made to perfect this technology but we can get there one day.
http://www.wired.com/magazine/2009/10/mf_optigenetics/3/
posted by Ronnie Newton at 12:22 PM
0 Comments:
Post a Comment
<< Home