Optogenetic methods to control excitation and inhibition of neuromuscular activity
- The goal of this dissertation was to develop new methods for optical inhibition of motor neuron and muscle activity to enable studies of neuromuscular control and provide therapeutic insights into disorders of the peripheral nervous system. Optogenetic methods have been used widely in the central nervous system, and for applications of optogenetics in the peripheral nervous system, the work of this dissertation focused on the development of new technologies for light delivery to peripheral nerves, modulation of peripheral nerve temperature, and control of excitation and inhibition of motor neuron and muscle activity. We developed an optogenetics based method that utilizes the chloride pump halorhodopsin (eNpHR2.0) to achieve precise and rapidly reversible optical inhibition of motor neuron and muscle activity in vivo in transgenic Thy1-eNpHR2.0-EYFP mice by illuminating the nerve with green light. We used this method to demonstrate that eNpHR2.0 is capable of intercepting spikes in the axon, optical inhibition is effective at all amplitudes of electrically evoked twitch force, and light power density modulates the degree of inhibition. This study revealed the potential of eNpHR2.0 as a powerful tool for inhibiting motor neuron and muscle activity in the peripheral nervous system. We developed a second method that utilizes in a new way the cation channel channelrhodopsin-2 (ChR2) to inhibit motor neuron and muscle activity in vivo in the cooled sciatic nerve of Thy1-ChR2-EYFP mice by illuminating the nerve with high frequency blue light pulses or continuous blue light. We identified light pulse frequency and nerve temperature as important variables for achieving inhibition and quantified their effects. This study presents an all-optical, single opsin and single wavelength method to control neuronal excitation and inhibition without requiring co-expression of excitatory and inhibitory opsins. This dissertation contributes new methods for optical inhibition of motor neuron and muscle activity and facilitates studies of neuromuscular control and treatment strategies for disorders of the peripheral nervous system.
|Type of resource
|electronic; electronic resource; remote
|1 online resource.
|Liske, Holly Anne
|Stanford University, Department of Mechanical Engineering.
|Statement of responsibility
|Holly Anne Liske.
|Submitted to the Department of Mechanical Engineering.
|Ph.D. Stanford University 2014
- © 2014 by Holly Liske
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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