Tiny and transparent<\/strong><\/h2>\nThe new EEG microarray, described today in Science Advances<\/a>, combines two key advantages. First, the electrodes are placed very close together on the surface of the cortex \u2014 a few micrometers apart, as opposed to millimeters currently. This enables researchers to collect very fine-grained information, down to the level of single neurons.<\/p>\nSecond, the team applied nanotechnologies to make the electrodes transparent. This allows light to pass through the electrode array so that the brain can be imaged at the same time.<\/p>\n
In experiments, Fagiolini and her team placed this transparent microarray on the visual cortex of live, awake mice. They were able to capture the electrical outputs of individual neurons as they responded to visual stimuli, while simultaneously obtaining high-resolution optical images.<\/p>\n
\u201cThis allows us to do experiments that were not possible before,\u201d says Fagiolini, who studies alterations of visual perception in Rett syndrome<\/a> in Boston Children\u2019s F.M. Kirby Neurobiology Center<\/a>. \u201cIn Rett syndrome, for example, we can know which specific groups of neurons are generating the abnormal EEG signals we\u2019ve been observing. Or we can see how particular cell populations are impacted by abnormal electrical signaling.\u201d<\/p>\nThe transparent nature of the electrodes also enables researchers to do optogenetics experiments (genetically altering cells using light) in conjunction with EEG. \u201cWe can then ask, if I perturb these cells, what happens to the EEG?\u201d says Fagiolini.<\/p>\n
Building a better microelectrode array<\/strong><\/h2>\nFang, co-senior author on the paper with Fagiolini, explains that transparent microelectrodes have been developed in the past using different materials such as graphene, but suffer from poor performance. Fang\u2019s team went back to existing electrode materials and turned to nanotechnology to fabricate a fine, two-layered mesh.<\/p>\n
\u201cWhat\u2019s remarkable is that by simple nanomeshing, we show that conventional electrode materials can be made transparent, while not compromising electrode performance,\u201d says Fang, whose lab is developing novel neurotechnologies in Northeastern\u2019s\u00a0Electrical and Computer Engineering Department.<\/a><\/p>\nAnother helpful feature is that the microelectrode arrays are soft, flexible and more biocompatible. This allows them to be implanted more safely on the brain, or a section of the brain, and remain for longer periods. Unlike most current electrodes, which are rigid, they conform to the brain\u2019s curvature \u2014 a helpful feature for application to humans, whose brains are highly convoluted.<\/p>\n
Advancing neuroscience with transparent microelectrodes<\/strong><\/h2>\nFagiolini envisions using the technology to study a variety of neurologic conditions, including traumatic brain injury and spinal cord injury. Interest is spreading among neuroscientists at Boston Children\u2019s. Fagiolini plans to work with hospital colleagues to develop computational algorithms to better interpret the paired EEG and imaging data.<\/p>\n
The team has filed a patent and plans to further refine the electrode microarray, make the system wireless and move to testing in primates and eventually humans. Patients undergoing neurosurgery for conditions such as epilepsy could be among the first test subjects, since they already have EEG arrays implanted to help identify a safe path for surgery.<\/p>\n
A much longer-range goal is to stimulate neurons through the electrodes to adjust their activity, rather than simply record their signals. Such stimulation could potentially have\u00a0therapeutic applications.<\/p>\n
Yi Qiang and Kyung Jin Seo of Northeastern University and Pietro Artoni of Boston Children\u2019s Hospital are co-first authors on the paper.\u00a0The study was supported by Northeastern University, the NIH National Institute of\u2028Neurological Disorders and Stroke (R01NS095959), Rettsyndrome.org, Rett Syndrome Research Trust, Simon Foundation, Human Frontier Science Program\u2013Cross-Disciplinary Fellowships, Endowment for the Chan Soon-Shiong Bionic Engineering Research Center, and University of California, Los Angeles. <\/br>See the paper<\/a> for a full list of authors and acknowledgements.<\/p>\nSee News@Northeastern<\/a> for more on this story, and read more about research at the FM Kirby Neurobiology Center<\/a>.<\/p>\n![\"\"](\"http:\/\/ircn.jp\/wp-content\/uploads\/2018\/09\/0e537eac2d23febcd44df5ac31b99311.jpg\")
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Second, the team applied nanotechnologies to make the electrodes transparent. This allows light to pass through the electrode array so that the brain can be imaged at the same time.<\/p>\n
In experiments, Fagiolini and her team placed this transparent microarray on the visual cortex of live, awake mice. They were able to capture the electrical outputs of individual neurons as they responded to visual stimuli, while simultaneously obtaining high-resolution optical images.<\/p>\n
\u201cThis allows us to do experiments that were not possible before,\u201d says Fagiolini, who studies alterations of visual perception in Rett syndrome<\/a> in Boston Children\u2019s F.M. Kirby Neurobiology Center<\/a>. \u201cIn Rett syndrome, for example, we can know which specific groups of neurons are generating the abnormal EEG signals we\u2019ve been observing. Or we can see how particular cell populations are impacted by abnormal electrical signaling.\u201d<\/p>\n The transparent nature of the electrodes also enables researchers to do optogenetics experiments (genetically altering cells using light) in conjunction with EEG. \u201cWe can then ask, if I perturb these cells, what happens to the EEG?\u201d says Fagiolini.<\/p>\n Fang, co-senior author on the paper with Fagiolini, explains that transparent microelectrodes have been developed in the past using different materials such as graphene, but suffer from poor performance. Fang\u2019s team went back to existing electrode materials and turned to nanotechnology to fabricate a fine, two-layered mesh.<\/p>\n \u201cWhat\u2019s remarkable is that by simple nanomeshing, we show that conventional electrode materials can be made transparent, while not compromising electrode performance,\u201d says Fang, whose lab is developing novel neurotechnologies in Northeastern\u2019s\u00a0Electrical and Computer Engineering Department.<\/a><\/p>\n Another helpful feature is that the microelectrode arrays are soft, flexible and more biocompatible. This allows them to be implanted more safely on the brain, or a section of the brain, and remain for longer periods. Unlike most current electrodes, which are rigid, they conform to the brain\u2019s curvature \u2014 a helpful feature for application to humans, whose brains are highly convoluted.<\/p>\n Fagiolini envisions using the technology to study a variety of neurologic conditions, including traumatic brain injury and spinal cord injury. Interest is spreading among neuroscientists at Boston Children\u2019s. Fagiolini plans to work with hospital colleagues to develop computational algorithms to better interpret the paired EEG and imaging data.<\/p>\n The team has filed a patent and plans to further refine the electrode microarray, make the system wireless and move to testing in primates and eventually humans. Patients undergoing neurosurgery for conditions such as epilepsy could be among the first test subjects, since they already have EEG arrays implanted to help identify a safe path for surgery.<\/p>\n A much longer-range goal is to stimulate neurons through the electrodes to adjust their activity, rather than simply record their signals. Such stimulation could potentially have\u00a0therapeutic applications.<\/p>\n Yi Qiang and Kyung Jin Seo of Northeastern University and Pietro Artoni of Boston Children\u2019s Hospital are co-first authors on the paper.\u00a0The study was supported by Northeastern University, the NIH National Institute of\u2028Neurological Disorders and Stroke (R01NS095959), Rettsyndrome.org, Rett Syndrome Research Trust, Simon Foundation, Human Frontier Science Program\u2013Cross-Disciplinary Fellowships, Endowment for the Chan Soon-Shiong Bionic Engineering Research Center, and University of California, Los Angeles. <\/br>See the paper<\/a> for a full list of authors and acknowledgements.<\/p>\n See News@Northeastern<\/a> for more on this story, and read more about research at the FM Kirby Neurobiology Center<\/a>.<\/p>\nBuilding a better microelectrode array<\/strong><\/h2>\n
Advancing neuroscience with transparent microelectrodes<\/strong><\/h2>\n
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