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How a Neuron Talks to a Muscle

A review of Liu, Hollopeter &

Jorgensen, 2009

OpenWorm Journal Club

January 17th, 2015

Stephen Larson

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The video talking about these slides

Link to paper

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@eleanor_lutz

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C. Elegans Muscle Cell from Gao & Zhen 2010

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Muscle cells in c. elegans

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Optogenetics: Inserting light-sensitive ion channels in MUSCLE

Amplifier

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Amplifier / Stimulator

muscle cell

ion channels

current clamp

voltage clamp

Fig 2. A&B, Boyle & Cohen, 2008

  • Repeated trials in each mode overlaid on top of each other
  • Top trace is recording, bottom trace is stimulus
  • A) shows results in milliVolts, B) shows results in nanoAmps

electrode

What dynamics of the muscle cell do we want to reproduce?

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Optogenetics: Inserting light-sensitive ion channels in NEURON

Amplifier

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Optogenetics: Inserting light-sensitive INHIBITORY ion channels in NEURON

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With trains of input vs. continuous & recovery

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Stimulating electrically vs. w/ light

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Post-synaptic currents with different frequencies of neuron stimulation

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Examples of post-synaptic currents depending on worm mutation

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Contributions

  • Muscle cells are stimulated by neurotransmitter release at the synaptic cleft
  • Optogenetics can be used to stimulate muscle cells directly with light
  • Optogenetics can be used to stimulate neurons with light that stimulate the muscle cells via neurotransmitter
  • Repeated trains of stimulation provides info on dynamics of synapse

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Follow up links