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In vivo Optogenetic Stimulation of the Rodent Central Nervous System
Published on: January 15, 2015
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Fatigue-resistant hydrogel optical fibers enable peripheral nerve optogenetics during locomotion
Xinyue Liu1,2, Siyuan Rao3,4, Weixuan Chen5
1Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA. xyliu@msu.edu.
Nature Methods
|October 19, 2023
Summary
Researchers created flexible, durable hydrogel optical fibers for optogenetics in moving animals. These fibers enable precise nerve stimulation and inhibition, advancing peripheral nerve research and somatosensation studies.
Area of Science:
- Biomaterials Science
- Neuroscience
- Optogenetics
Background:
- Optogenetic modulation of peripheral nerves is crucial for understanding neural circuits and treating neurological disorders.
- Existing methods often lack the flexibility and durability required for chronic in vivo applications, especially during animal movement.
Purpose of the Study:
- To develop soft, stretchable, and fatigue-resistant hydrogel optical fibers for long-term optogenetic control of peripheral nerves.
- To demonstrate the efficacy of these fibers in enabling optogenetic activation and inhibition in freely behaving animals during locomotion and over extended periods.
Main Methods:
- Fabrication of hydrogel optical fibers incorporating polymeric nanocrystalline domains for enhanced mechanical and optical properties.
- In vivo implantation of fibers into the sciatic nerve of mice (Thy1::ChR2 and TRPV1::NpHR models).
- Assessment of fiber performance during chronic optogenetic activation of hindlimb muscles and optical inhibition of pain hypersensitivity during voluntary wheel running.
Main Results:
- Hydrogel fibers exhibited low optical losses (1.07 dB/cm), high stretchability (200%), and excellent fatigue resistance (1.4 MPa after 30,000 cycles).
- Successful optogenetic activation of hindlimb muscles in Thy1::ChR2 mice during 6 weeks of continuous wheel running.
- Effective optical inhibition of pain hypersensitivity in TRPV1::NpHR mice over an 8-week period.
Conclusions:
- The developed hydrogel optical fibers provide a robust, motion-adaptable platform for peripheral nerve optogenetics.
- These fibers facilitate long-term, in vivo studies of neural function and therapeutic interventions in freely behaving animals.
- This technology opens new avenues for investigating somatosensation and developing novel treatments for neuropathic pain and other neurological conditions.
