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Optimization of genetically encoded GABA indicator

posted on 15.09.2022, 21:36 authored by Ilya KolbIlya Kolb, Jeremy HassemanJeremy Hasseman, Getahun Tsegaye, Arthur Tsang, Daniel Reep, Jihong ZhengJihong Zheng, Ben ArthurBen Arthur, Jonathan S. Marvin, Karel SvobodaKarel Svoboda, Loren L Looger, Wyatt KorffWyatt Korff, GENIE Project Team


The GENIE Project Team at HHMI Janelia has developed a  second-generation genetically encoded GABA indicator, in collaboration  with Jonathan Marvin and Loren Looger. The sensor is based on iGABASnFR  (1), and has the following features, tested extensively in cultured  neurons:

  • Positive-going version (iGABASnFR2) and negative-going version (iGABASnFR2n)
  • iGABASnFR2: 4x higher sensitivity to APs than iGABASnFR, iGABASnFR2n: 2x higher sensitivity to APs than iGABASnFR.
  • Both enable single-AP high-speed imaging
  • Enables detection of signal in individual dendrites and synaptic boutons
  • Higher affinity for GABA (iGABASnFR2: EC50: 6.4±0.2 μM, ~7x tighter than iGABASnFR, ΔF/Fmax=0.5±0.05, ~2x higher than iGABASnFR)
  • Imaged with standard GFP filter set




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