Karl Deisseroth has created new tools and techniques to advance the study of diseases through optogenetics. The molecular technique used is able to control whole circuits of neurons instead of only a single cell. This technique will allow scientist to study specific neural networks in the brain. Another improvement in this field is the use of a near-infrared technique which will allow noninvasive procedures to occur while still reaching the brain cells in the deep tissue. Currently, a fiber-optic cable is implanted into an animal’s brain to deliver the light activation to the cells. Lastly, the “off switch” has been improved to make “target neuron more sensitive to light [which] allows for tighter neural control”.
The new off switch is twenty times more responsive than yellow light used in previous generations. Also, the future looks prosperous since red and near-infrared light in known to be able to penetrate deeper into tissue. In one study, Jerry Silver used optogenetics to explore bladder control after spinal cord injuries. He turned off the nerves located in the lower spine that relax the bladder. However, he has noted how, in the past, the use of so much light creates too much heat. The new tools, he believes, seem to need less light which would produce less heat while being able to invade farther into the tissue. He is extremely hopeful of the future.
Another application of optogenetics is being led by Richard H. Kramer who believes that restoration of sight can be achieved through the use of labels. Kramers technique is different because he uses photosensitive compounds which will attach to cells through chemical means rather than using genetic engineering. He and his colleagues focus on potassium channels and manipulate the activation or inhibition of neurons through these channels. Next, “to attach the label, the researchers simply bathe cells in a solution containing the molecule.” A molecule called azobenzene, a photoisomer, changes its physical but not chemical composition when exposed to light. The label will actually allow the neuron to be illuminated continuously. This connects with Kramer’s goal to restore sight because he says, “The long-term hope is that something like the compounds we've developed might be able to restore sight using cells that aren't normally light sensitive." Therefore, although cones or retina’s rods may have been damaged, other nerve cells can be made to pick up photons which normally do not. However, this is still in the early stages and the side effects of such actions have yet to be observed in animals. Regardless, the new field and technology of optogenetics seems promising and capable of benefiting a broad range of problems from depression and Parkinson’s disease to the loss of sight.
The new off switch is twenty times more responsive than yellow light used in previous generations. Also, the future looks prosperous since red and near-infrared light in known to be able to penetrate deeper into tissue. In one study, Jerry Silver used optogenetics to explore bladder control after spinal cord injuries. He turned off the nerves located in the lower spine that relax the bladder. However, he has noted how, in the past, the use of so much light creates too much heat. The new tools, he believes, seem to need less light which would produce less heat while being able to invade farther into the tissue. He is extremely hopeful of the future.
Another application of optogenetics is being led by Richard H. Kramer who believes that restoration of sight can be achieved through the use of labels. Kramers technique is different because he uses photosensitive compounds which will attach to cells through chemical means rather than using genetic engineering. He and his colleagues focus on potassium channels and manipulate the activation or inhibition of neurons through these channels. Next, “to attach the label, the researchers simply bathe cells in a solution containing the molecule.” A molecule called azobenzene, a photoisomer, changes its physical but not chemical composition when exposed to light. The label will actually allow the neuron to be illuminated continuously. This connects with Kramer’s goal to restore sight because he says, “The long-term hope is that something like the compounds we've developed might be able to restore sight using cells that aren't normally light sensitive." Therefore, although cones or retina’s rods may have been damaged, other nerve cells can be made to pick up photons which normally do not. However, this is still in the early stages and the side effects of such actions have yet to be observed in animals. Regardless, the new field and technology of optogenetics seems promising and capable of benefiting a broad range of problems from depression and Parkinson’s disease to the loss of sight.
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1 comment:
Mary, it seems that continuation of research in the field of optogenetics can lead to several medical breakthroughs. As you mentioned, the light-activation techniques are non-invasive, which allows for the studying of cells deep in the brain tissue. This has allowed for collection of specific neural data that was previously unobtainable. It was interesting to find that Ed Boyden, Karl Deisseroth's colleague, is involved in his own company, Eos, which is specializing in optogenetic research to treat blindness. However, he does maintain that such practices may never be safe enough for human application.
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