TY - GEN
T1 - Computational model of optogenetic stimulation in a peripheral nerve
AU - Fritz, Nicholas
AU - Gulick, Daniel
AU - Blain Christen, Jennifer
N1 - Funding Information:
This work is supported by the National Science Foundation under Grant No. ECCS:1554690, CAREER: Adapting Flexible Display Technology for Optogenetic Peripheral Nerve Stimulation.
Funding Information:
This work is supported by the National Science Foundation under Grant No. ECCS:1554690, CAREER: Adapting Flexible Display Technology for Optogenetic Peripheral Nerve Stimulation. All experiments were conducted under protocol 16-1483R approved by the Institutional Animal Care and
Publisher Copyright:
© 2018 IEEE.
PY - 2018/12/10
Y1 - 2018/12/10
N2 - Stimulation has been a key technique for studying underlying mechanisms of the nervous system. Electrical stimulation has been the predominant method for eliciting desired muscle responses for decades, yet methodologies remain invasive and low in selectivity of tissue stimulated. Current injection affects all local tissue types and can lead to damaging immune responses that threaten both nerves and equipment alike. Optogenetics provides a solution for such stimulation difficulties by increasing specificity and decreasing risk to tissue. Via genetic modifications, opsins (light-sensitive proteins) are added to neurons, and can be activated by light to cause neuron excitation. Through preliminary in vivo testing in transgenic mice expressing channelrhodopsin (ChR2) we validate that multiple beams of light have an additive effect and increase the response from muscles innervated by the target nerve. Measuring hindlimb flexion increases with increase in number of light sources present. To further characterize this additive effect, a Monte Carlo computer model was generated to simulate a random-walk of photons passing through nerve tissue. The model shows that light beams can aggregate within the nerve, although are limited. When using collimated light, multiple beams converging on the interior region of the nerve cannot result in a higher intensity than outermost layer of tissue nearest a single light source. This model serves as a tool to aid future animal studies by determining light emission parameters, specifically prescribing the need for optically-focused light, when attempting to selectively stimulate regions deep in the interior of a given nerve. Such capability will allow for high spatial resolution of stimulation in peripheral nerves giving finer control of excitation in downstream tissue.
AB - Stimulation has been a key technique for studying underlying mechanisms of the nervous system. Electrical stimulation has been the predominant method for eliciting desired muscle responses for decades, yet methodologies remain invasive and low in selectivity of tissue stimulated. Current injection affects all local tissue types and can lead to damaging immune responses that threaten both nerves and equipment alike. Optogenetics provides a solution for such stimulation difficulties by increasing specificity and decreasing risk to tissue. Via genetic modifications, opsins (light-sensitive proteins) are added to neurons, and can be activated by light to cause neuron excitation. Through preliminary in vivo testing in transgenic mice expressing channelrhodopsin (ChR2) we validate that multiple beams of light have an additive effect and increase the response from muscles innervated by the target nerve. Measuring hindlimb flexion increases with increase in number of light sources present. To further characterize this additive effect, a Monte Carlo computer model was generated to simulate a random-walk of photons passing through nerve tissue. The model shows that light beams can aggregate within the nerve, although are limited. When using collimated light, multiple beams converging on the interior region of the nerve cannot result in a higher intensity than outermost layer of tissue nearest a single light source. This model serves as a tool to aid future animal studies by determining light emission parameters, specifically prescribing the need for optically-focused light, when attempting to selectively stimulate regions deep in the interior of a given nerve. Such capability will allow for high spatial resolution of stimulation in peripheral nerves giving finer control of excitation in downstream tissue.
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U2 - 10.1109/LSC.2018.8572187
DO - 10.1109/LSC.2018.8572187
M3 - Conference contribution
AN - SCOPUS:85060237421
T3 - 2018 IEEE Life Sciences Conference, LSC 2018
SP - 154
EP - 158
BT - 2018 IEEE Life Sciences Conference, LSC 2018
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2018 IEEE Life Sciences Conference, LSC 2018
Y2 - 28 October 2018 through 30 October 2018
ER -