DEEP BRAIN PHOTONIC TOOLS FOR CELL-TYPE SPECIFIC TARGETING OF NEURAL DISEASES
Published February 10, 2022 | Version v1
Journal article Open

A genetically encoded sensor for in vivo imaging of orexin neuropeptides.

Creators

  • 1. Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
  • 2. Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
  • 3. Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
  • 4. Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital University Hospital Bern, University of Bern, Bern, Switzerland
  • 5. Circuits for Emotion Research Group, Max Planck Institute of Neurobiology, Martinsried, Germany
  • 6. Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland

Description

Orexins (also called hypocretins) are hypothalamic neuropeptides that carry out essential functions in the central nervous system; however, little is known about their release and range of action in vivo owing to the limited resolution of current detection technologies. Here we developed a genetically encoded orexin sensor (OxLight1) based on the engineering of circularly permutated green fluorescent protein into the human type-2 orexin receptor. In mice OxLight1 detects optogenetically evoked release of endogenous orexins in vivo with high sensitivity. Photometry recordings of OxLight1 in mice show rapid orexin release associated with spontaneous running behavior, acute stress and sleep-to-wake transitions in different brain areas. Moreover, two-photon imaging of OxLight1 reveals orexin release in layer 2/3 of the mouse somatosensory cortex during emergence from anesthesia. Thus, OxLight1 enables sensitive and direct optical detection of orexin neuropeptides with high spatiotemporal resolution in living animals.

Notes

The results are part of a project that has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no. 891959; to T.P.). We also acknowledge funding from the University of Zurich and the Swiss National Science Foundation (grant no. 310030_196455; to T.P.); Forschungskredit Candoc (to X.Z.); ETH Zurich (to D.B.); Swiss National Science Foundation (grant no. PCEFP3_181282; to M.S.); ERC-2017-STG (grant agreement no. 758448; to N.G.); Swiss National Science Foundation and ERC-2016-CoG (grant agreement no. 725850) (A.R.A.); University of Bern and Inselspital University Hospital (A.R.A. and M.H.S.); ERC-2014-CoG (grant agreement no. 647725) and National Institutes of Health Brain Initiative (U19 NS107464) (both to T.F.); H2020-ICT (grant agreement no. 101016787; to T.P. and T.F.). We thank J.-C. Paterna and the VVF of the Neuroscience Center Zurich for help with virus production, M. Drobizhev (Montana State University) for sharing the Rh6G reference two-photon spectrum and useful insights and F. Succol for technical support and for performing IHC and confocal image acquisition. The plasmids coding for mini-Gi-mRuby2, mini-Gs-mRuby2 and mini-Gq-mRuby2 were a kind gift from N. Lambert (Augusta University). The Alexa-647 labeled M1 anti-FLAG antibody was a kind gift from M. von Zastrow (University of California San Francisco).

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Additional details

Related works

Is identical to
10.1038/s41592-021-01390-2 (DOI)

Funding

OPTONEUROCHEM – Genetically encoded sensors for imaging neurochemical dynamics in vivo 891959
European Commission
InsularAnxiety – Insular cortical circuits controlling fear and anxiety 758448
European Commission
NEURO-PATTERNS – How neuronal activity patterns drive behavior: novel all-optical control and monitoring of brain neuronal networks with high spatiotemporal resolution 647725
European Commission
Mechanisms Underlying Subcellular Location Bias of Opioid Receptor Signaling PCEFP3_181282
Swiss National Science Foundation
Dissecting MCH and DA dynamics in vivo with novel genetically encoded sensors 310030_196455
Swiss National Science Foundation
Opto-Sleep – All-optical deconstruction of thalamic control of sleep-wake states. 725850
European Commission
DEEPER – DEEP BRAIN PHOTONIC TOOLS FOR CELL-TYPE SPECIFIC TARGETING OF NEURAL DISEASES 101016787
European Commission