Department of Biomedical Engineering Final Oral Examination Komal Kampasi Implantable Low-Noise Fiberless Optoelectrodes for Optogenetic Control of Distinct Neural Populations The mammalian brain is often compared to an electrical circuit, and its dynamics
Department of Biomedical Engineering Final Oral Examination
Implantable Low-Noise Fiberless Optoelectrodes for Optogenetic Control of Distinct Neural Populations
The mammalian brain is often compared to an electrical circuit, and its dynamics and function are governed by communication across different types neurons. To treat many neurological disorders, which are characterized by inhibition or amplification of neural activity in a particular region or lack of communication between cell types, there is a need to troubleshoot neural networks at cellular or local circuit level with the help of innovative implantable neural technologies. Though optogenetics has proven to be the most powerful means of cell-type specific neural circuit control in recent years, a long-standing question in neuroscience has been whether it is possible to achieve independent control of two or more distinct neural populations simultaneously. In this work, we introduce a novel implantable optoelectrode that can manipulate more than one neuron type at a single site, independently and simultaneously. By delivering multi-color light using a scalable optical waveguide mixer, we demonstrate manipulation of multiple neuron types in precise spatial locations. We report design, micro-fabrication and optoelectronic packaging of a fiber-less, multicolor optoelectrode that is also scalable, modular and minimally invasive. The compact optoelectrode design consists of 7 μm x 30 μm dielectric optical waveguide mixers monolithically integrated on a 22μm-thick four-shank silicon neural probe. The waveguide mixers are coupled to eight side-emitting injection laser diodes (ILDs) via gradient-index (GRIN) lenses assembled on the probe backend. We explain that a GRIN-based optoelectrode design offers superior optical, thermal and electrical performance and a longer device life than other available optoelectrode designs. The packaged devices were validated in densely populated CA1 pyramidal layer of rodent hippocampus both in anesthetized and awake behaving animals. High quality neural recording and successful manipulation of a variety of multi-opsin cell preparations expressing Channelrhodopsin-2, Archaerhodopsin and ChrimsonR demonstrate potential use of this technology in the functional dissection of neural circuits. The ultimate goal is to solve critical aims in neuroscience like closed loop excitation and the study of neural plasticity, allowing researchers to ultimately understand mysteries of neurological disorders like Alzheimer’s and Parkinson’s.
Date: Wednesday, March 29, 2017
Time: 9:00 AM
Location: GM Room, Lurie Engineering Center (LEC)
Chair: Dr. Euisik Yoon
(Wednesday) 9:00 am - 10:00 am
General Motors Conference Room in Lurie Engineering Center (LEC)
Featuring talented keynote speakers from across the world as well as six “mini-talks” presentations from across the University The symposium will bring together national leaders of the scientific, medical and engineering communities
Featuring talented keynote speakers from across the world as well as six “mini-talks” presentations from across the University
The symposium will bring together national leaders of the scientific, medical and engineering communities working on recent advances of our understanding of RNA. It will provide a means of exchanging new ideas across disciplines, spurring new collaborations across campus and nationwide while supporting a rapidly growing RNA community at the U-M. Further augmenting the Block of MCubes 2.0 focused on RNA, this symposium will herald the Center for RNA Biomedicine at the U-M. This symposium is open to University of Michigan clinicians and research scientists, as well as other primary care practitioners and public health scholars interested in the most recent discoveries regarding the role of RNA in health and disease.
More info here: http://www.umichrna.org/2017-symposium/
(Friday) 8:45 am - 3:30 pm
Biomedical Science Research Building (BSRB)