NEUROSCIENCE. Natural light-gated anion channels: A family of microbial rhodopsins for advanced optogenetics

Science. 2015 Aug 7;349(6248):647-50. doi: 10.1126/science.aaa7484. Epub 2015 Jun 25.


Light-gated rhodopsin cation channels from chlorophyte algae have transformed neuroscience research through their use as membrane-depolarizing optogenetic tools for targeted photoactivation of neuron firing. Photosuppression of neuronal action potentials has been limited by the lack of equally efficient tools for membrane hyperpolarization. We describe anion channel rhodopsins (ACRs), a family of light-gated anion channels from cryptophyte algae that provide highly sensitive and efficient membrane hyperpolarization and neuronal silencing through light-gated chloride conduction. ACRs strictly conducted anions, completely excluding protons and larger cations, and hyperpolarized the membrane of cultured animal cells with much faster kinetics at less than one-thousandth of the light intensity required by the most efficient currently available optogenetic proteins. Natural ACRs provide optogenetic inhibition tools with unprecedented light sensitivity and temporal precision.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chloride Channels / classification
  • Chloride Channels / genetics
  • Chloride Channels / physiology*
  • Cryptophyta / genetics
  • Cryptophyta / metabolism*
  • HEK293 Cells
  • Humans
  • Ion Channel Gating
  • Light
  • Membrane Potentials / physiology
  • Membrane Potentials / radiation effects*
  • Molecular Sequence Data
  • Neural Inhibition
  • Neurons / physiology
  • Neurons / radiation effects*
  • Optogenetics / methods*
  • Photic Stimulation
  • Phylogeny
  • Rhodopsins, Microbial / classification
  • Rhodopsins, Microbial / genetics
  • Rhodopsins, Microbial / physiology*
  • Transfection


  • Chloride Channels
  • Rhodopsins, Microbial