Post by Suu on Sept 22, 2015 5:54:11 GMT -5
Findings:
Light has been used for imaging neural activity in technologies such as DOT (diffuse optical tomography) and fluorescence imaging. Light however, can also be used to stimulate neural activity as well, in a manner which provides benefits over the current gold standard of electrical stimulation. Using light to stimulate neuronal activity provides the benefits of: little to no tissue damage, better manipulation of space, and doesn't interfere with itself. These properties give a significant advantage over the standard electrical stimulation, which can cause necrosis and inflammation, is limited to areas of contact, and has no real spatial precision. Optical Stimulation can also inhibit neural stimulation, which I will not go into in this report.
Although there are a few methods for Neural Stimulation through EM radiation, the particular method that we are looking at is Infrared Neural Stimulation. Infrared light is used induce an electrical signal within a targeted neurons. How infrared light does this is poorly understood however, but is known to be the effect from the heating of neurons. Research is currently being undertaken to understand the exact mechanisms which cause this phenomenon. Light has been used for imaging neural activity in technologies such as DOT (diffuse optical tomography) and fluorescence imaging. Light however, can also be used to stimulate neural activity as well, in a manner which provides benefits over the current gold standard of electrical stimulation. Using light to stimulate neuronal activity provides the benefits of: little to no tissue damage, better manipulation of space, and doesn't interfere with itself. These properties give a significant advantage over the standard electrical stimulation, which can cause necrosis and inflammation, is limited to areas of contact, and has no real spatial precision. Optical Stimulation can also inhibit neural stimulation, which I will not go into in this report.
Optical stimulation has the unique advantage of not requiring direct contact with tissue, which gives it spacial precision. This also makes it so there is no inflammation or necrosis from the storage of charge elicited through the use of electrodes. However, Infrared light can cause damage to heat-related damage from repeated heating over a short period of time. This can be circumvented through the effective use of wavelengths of light, changing it into the optimal wavelength for specific groups of nerves.
This technology has been used to successfully stimulate muscle neurons, causing activation of muscle fiber, and also has been successfully demonstrated as a peacemaker for a embryo. This proves the concept of Infrared Nerve Stimulation. There is currently research being done in the use of infrared light in place of electrical cochlear implants.
However, there has been some unexpected results, specifically in the inability for optical light to effectively activate cochlear nerves. This is believed to be caused by a difference in cochlear nerves to other nerve types, and is currently being investigated.
Studies have shown that the combination of electrical stimulation and optical stimulation lessens the threshold required for stimulation of cells, by around 300%. This suggests that electrical and optical stimulation can be combined to be even more effective than by themselves.
Optical neural stimulation is a relatively new field in neuroscience, and one which shows great promise in the future.
Cost/ Feasibility:
Not applicable at this stage. Very, very feasible though.
Personal Comments:
This new technology is honestly fascinating, and exciting, and I have high hopes for the application of this technology in this field.
It may even be the difference from having ugly electrodes planted into people and being able to use this product without contact.
Sources
1.) Warden, Melissa R., Jessica A. Cardin, and Karl Deisseroth. "Optical Neural Interfaces." Annual Review of Biomedical Engineering. U.S. National Library of Medicine, n.d. Web. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4163158/>
2.) Jansen, E. Duco. "Optical Stimulation of Neural Tissue: Current State and Future Challenges." Vanderbilt, 23 Nov. 2011. Web. <http://www.bionicsinstitute.org/news/Conference_Presentations/0830-0900%20E%20Duco%20Jansen.pdf>
3.) Jenkins, M. W., A. R. Duke, S. Gu, H. J. Chiel, H. Fujioka, M. Watanabe, E. D. Jansen, and A. M. Rollins. "Optical Pacing of the Embryonic Heart." Nature Photonics. U.S. National Library of Medicine, n.d. Web. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3059323/>
4.) Wells, Jonathon, Mark Bendett, Daniel J. Lee, Jonathan Cayce, Austin Duke, and Agnella Izzo Matic. "Infrared Nerve Stimulation: Hearing by Light." BioOptics World. PennWell Corporation, 11 Jan. 2008. Web. <http://www.bioopticsworld.com/articles/print/volume-1/issue-6/features/neurological-treatment/infrared-nerve-stimulation-hearing-by-light.html>