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  • Review Article
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Optical control of neuronal ion channels and receptors

Abstract

Light-controllable tools provide powerful means to manipulate and interrogate brain function with relatively low invasiveness and high spatiotemporal precision. Although optogenetic approaches permit neuronal excitation or inhibition at the network level, other technologies, such as optopharmacology (also known as photopharmacology) have emerged that provide molecular-level control by endowing light sensitivity to endogenous biomolecules. In this Review, we discuss the challenges and opportunities of photocontrolling native neuronal signalling pathways, focusing on ion channels and neurotransmitter receptors. We describe existing strategies for rendering receptors and channels light sensitive and provide an overview of the neuroscientific insights gained from such approaches. At the crossroads of chemistry, protein engineering and neuroscience, optopharmacology offers great potential for understanding the molecular basis of brain function and behaviour, with promises for future therapeutics.

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Fig. 1: Main strategies to endow light sensitivity to neuronal receptors and ion channels.
Fig. 2: Photocontrol of ion channel and receptor biophysics and pharmacology.
Fig. 3: Optopharmacology for subcellular neuronal studies.
Fig. 4: Optopharmacology for cell-specific and receptor-specific interrogation of synaptic physiology.
Fig. 5: Optopharmacology for behavioural studies.

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References

  1. Hille, B. Ionic Channels of Excitable Membranes 3rd edn (Sinauer Associates, 2001).

  2. Lemoine, D. et al. Ligand-gated ion channels: new insights into neurological disorders and ligand recognition. Chem. Rev. 112, 6285–6318 (2012).

    Article  CAS  PubMed  Google Scholar 

  3. Smart, T. G. & Paoletti, P. Synaptic neurotransmitter-gated receptors. Cold Spring Harb. Perspect. Biol. 4, a009662 (2012).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  4. Foster, D. J. & Conn, P. J. Allosteric modulation of GPCRs: new insights and potential utility for treatment of schizophrenia and other CNS disorders. Neuron 94, 431–446 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Rask-Andersen, M., Almen, M. S. & Schioth, H. B. Trends in the exploitation of novel drug targets. Nat. Rev. Drug Discov. 10, 579–590 (2011).

    Article  CAS  PubMed  Google Scholar 

  6. Coetzee, W. A. et al. Molecular diversity of K+ channels. Ann. NY Acad. Sci. 868, 233–285 (1999).

    Article  CAS  PubMed  Google Scholar 

  7. Engin, E., Benham, R. S. & Rudolph, U. An emerging circuit pharmacology of GABAA receptors. Trends Pharmacol. Sci. 39, 710–732 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Kramer, R. H., Mourot, A. & Adesnik, H. Optogenetic pharmacology for control of native neuronal signaling proteins. Nat. Neurosci. 16, 816–823 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  9. Scanziani, M. & Hausser, M. Electrophysiology in the age of light. Nature 461, 930–939 (2009).

    Article  CAS  PubMed  Google Scholar 

  10. Kim, C. K., Adhikari, A. & Deisseroth, K. Integration of optogenetics with complementary methodologies in systems neuroscience. Nat. Rev. Neurosci. 18, 222–235 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Bartels, E., Wassermann, N. H. & Erlanger, B. F. Photochromic activators of the acetylcholine receptor. Proc. Natl Acad. Sci. USA 68, 1820–1823 (1971).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Lester, H. A., Krouse, M. E., Nass, M. M., Wassermann, N. H. & Erlanger, B. F. Light-activated drug confirms a mechanism of ion channel blockade. Nature 280, 509–510 (1979).

    Article  CAS  PubMed  Google Scholar 

  13. Kaplan, J. H., Forbush, B. 3rd & Hoffman, J. F. Rapid photolytic release of adenosine 5′-triphosphate from a protected analogue: utilization by the Na:K pump of human red blood cell ghosts. Biochemistry 17, 1929–1935 (1978).

    Article  CAS  PubMed  Google Scholar 

  14. Lester, H. A., Krouse, M. E., Nass, M. M., Wassermann, N. H. & Erlanger, B. F. A covalently bound photoisomerizable agonist: comparison with reversibly bound agonists at Electrophorus electroplaques. J. Gen. Physiol. 75, 207–232 (1980).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Ellis-Davies, G. C. Caged compounds: photorelease technology for control of cellular chemistry and physiology. Nat. Methods 4, 619–628 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Hamouda, A. K., Jayakar, S. S., Chiara, D. C. & Cohen, J. B. Photoaffinity labeling of nicotinic receptors: diversity of drug binding sites! J. Mol. Neurosci. 53, 480–486 (2014).

    Article  CAS  PubMed  Google Scholar 

  17. Berlin, S. & Isacoff, E. Y. Synapses in the spotlight with synthetic optogenetics. EMBO Rep. 18, 677–692 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Hüll, K., Morstein, J. & Trauner, D. In vivo photopharmacology. Chem. Rev. 118, 10710–10747 (2018).

    Article  PubMed  CAS  Google Scholar 

  19. Ellis-Davies, G. C. R. A chemist and biologist talk to each other about caged neurotransmitters. Beilstein J. Org. Chem. 9, 64–73 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Ellis-Davies, G. C. R. Two-photon uncaging of glutamate. Front. Synaptic Neurosci. 10, 48 (2019).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  21. Wilcox, M. et al. Synthesis of photolabile precursors of amino acid neurotransmitters. J. Org. Chem. 55, 1585–1589 (1990).

    Article  CAS  Google Scholar 

  22. Wieboldt, R. et al. Photolabile precursors of glutamate: synthesis, photochemical properties, and activation of glutamate receptors on a microsecond time scale. Proc. Natl Acad. Sci. USA 91, 8752–8756 (1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Matsuzaki, M. et al. Dendritic spine geometry is critical for AMPA receptor expression in hippocampal CA1 pyramidal neurons. Nat. Neurosci. 4, 1086–1092 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature 429, 761–766 (2004). This is the first evidence that LTP (spine growth and an increase in AMPAR current) can be induced at single spines using two-photon glutamate uncaging, in a non-Hebbian manner (that is, not requiring presynaptic release).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Gee, K. R., Wieboldt, R. & Hess, G. P. Synthesis and photochemistry of a new photolabile derivative of GABA-neurotransmitter release and receptor activation in the microsecond time region. J. Am. Chem. Soc. 116, 8366–8367 (1994).

    Article  CAS  Google Scholar 

  26. Rial Verde, E. M., Zayat, L., Etchenique, R. & Yuste, R. Photorelease of GABA with visible light using an inorganic caging group. Front. Neural Circuits 2, 2 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  27. Kantevari, S., Matsuzaki, M., Kanemoto, Y., Kasai, H. & Ellis-Davies, G. C. Two-color, two-photon uncaging of glutamate and GABA. Nat. Methods 7, 123–125 (2010).

    Article  CAS  PubMed  Google Scholar 

  28. Matsuzaki, M., Hayama, T., Kasai, H. & Ellis-Davies, G. C. R. Two-photon uncaging of gamma-aminobutyric acid in intact brain tissue. Nat. Chem. Biol. 6, 255–257 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Donato, L. et al. Water-soluble, donor-acceptor biphenyl derivatives in the 2-(o-nitrophenyl)propyl series: highly efficient two-photon uncaging of the neurotransmitter gamma-aminobutyric acid at lambda = 800 nm. Angew. Chem. Int. Ed. 51, 1840–1843 (2012).

    Article  CAS  Google Scholar 

  30. Araya, R., Andino-Pavlovsky, V., Yuste, R. & Etchenique, R. Two-photon optical interrogation of individual dendritic spines with caged dopamine. ACS Chem. Neurosci. 4, 1163–1167 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Breitinger, H. G., Wieboldt, R., Ramesh, D., Carpenter, B. K. & Hess, G. P. Synthesis and characterization of photolabile derivatives of serotonin for chemical kinetic investigations of the serotonin 5-HT(3) receptor. Biochemistry 39, 5500–5508 (2000).

    Article  CAS  PubMed  Google Scholar 

  32. Warther, D. et al. Two-photon uncaging: new prospects in neuroscience and cellular biology. Bioorg. Med. Chem. 18, 7753–7758 (2010).

    Article  CAS  PubMed  Google Scholar 

  33. Walker, J. W., McCray, J. A. & Hess, G. P. Photolabile protecting groups for an acetylcholine receptor ligand. Synthesis and photochemistry of a new class of o-nitrobenzyl derivatives and their effects on receptor function. Biochemistry 25, 1799–1805 (1986).

    Article  CAS  PubMed  Google Scholar 

  34. Milburn, T. et al. Synthesis, photochemistry, and biological activity of a caged photolabile acetylcholine receptor ligand. Biochemistry 28, 49–55 (1989).

    Article  CAS  PubMed  Google Scholar 

  35. Banala, S. et al. Photoactivatable drugs for nicotinic optopharmacology. Nat. Methods 15, 347–350 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Passlick, S., Thapaliya, E. R., Chen, Z., Richers, M. T. & Ellis-Davies, G. C. R. Optical probing of acetylcholine receptors on neurons in the medial habenula with a novel caged nicotine drug analogue. J. Physiol. 596, 5307–5318 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Niu, L., Wieboldt, R., Ramesh, D., Carpenter, B. K. & Hess, G. P. Synthesis and characterization of a caged receptor ligand suitable for chemical kinetic investigations of the glycine receptor in the 3-microseconds time domain. Biochemistry 35, 8136–8142 (1996).

    Article  CAS  PubMed  Google Scholar 

  38. Gee, K. R., Niu, L., Schaper, K., Jayaraman, V. & Hess, G. P. Synthesis and photochemistry of a photolabile precursor of N-methyl-D-aspartate (NMDA) that is photolyzed in the microsecond time region and is suitable for chemical kinetic investigations of the NMDA receptor. Biochemistry 38, 3140–3147 (1999).

    Article  CAS  PubMed  Google Scholar 

  39. Palma-Cerda, F. et al. New caged neurotransmitter analogs selective for glutamate receptor sub-types based on methoxynitroindoline and nitrophenylethoxycarbonyl caging groups. Neuropharmacology 63, 624–634 (2012).

    Article  CAS  PubMed  Google Scholar 

  40. Niu, L., Gee, K. R., Schaper, K. & Hess, G. P. Synthesis and photochemical properties of a kainate precursor and activation of kainate and AMPA receptor channels on a microsecond time scale. Biochemistry 35, 2030–2036 (1996).

    Article  CAS  PubMed  Google Scholar 

  41. Banghart, M. R. & Sabatini, B. L. Photoactivatable neuropeptides for spatiotemporally precise delivery of opioids in neural tissue. Neuron 73, 249–259 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Banghart, M. R., Williams, J. T., Shah, R. C., Lavis, L. D. & Sabatini, B. L. Caged naloxone reveals opioid signaling deactivation kinetics. Mol. Pharmacol. 84, 687–695 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Banghart, M. R., He, X. J. & Sabatini, B. L. A. Caged enkephalin optimized for simultaneously probing mu and delta opioid receptors. ACS Chem. Neurosci. 9, 684–690 (2018).

    Article  CAS  PubMed  Google Scholar 

  44. Volgraf, M. et al. Reversibly caged glutamate: a photochromic agonist of ionotropic glutamate receptors. J. Am. Chem. Soc. 129, 260–261 (2007).

    Article  CAS  PubMed  Google Scholar 

  45. Banghart, M. R. et al. Photochromic blockers of voltage-gated potassium channels. Angew. Chem. Int. Ed. 48, 9097–9101 (2009).

    Article  CAS  Google Scholar 

  46. Izquierdo-Serra, M. et al. Optical control of endogenous receptors and cellular excitability using targeted covalent photoswitches. Nat. Commun. 7, 12221 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Szymanski, W., Yilmaz, D., Kocer, A. & Feringa, B. L. Bright ion channels and lipid bilayers. Acc. Chem. Res. 46, 2910–2923 (2013).

    Article  CAS  PubMed  Google Scholar 

  48. Broichhagen, J. & Trauner, D. The in vivo chemistry of photoswitched tethered ligands. Curr. Opin. Chem. Biol. 21, 121–127 (2014).

    Article  CAS  PubMed  Google Scholar 

  49. Reiner, A., Levitz, J. & Isacoff, E. Y. Controlling ionotropic and metabotropic glutamate receptors with light: principles and potential. Curr. Opin. Pharmacol. 20, 135–143 (2015).

    Article  CAS  PubMed  Google Scholar 

  50. Fortin, D. L. et al. Photochemical control of endogenous ion channels and cellular excitability. Nat. Methods 5, 331–338 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Mourot, A. et al. Tuning photochromic ion channel blockers. ACS Chem. Neurosci. 2, 536–543 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Mourot, A. et al. Rapid optical control of nociception with an ion-channel photoswitch. Nat. Methods 9, 396–402 (2012). In this paper, a light-controllable lidocaine derivative was developed and targeted to pain-sensing neurons without requiring genetic modification, allowing photocontrol of pain signalling in living rats.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  53. Schonberger, M., Althaus, M., Fronius, M., Clauss, W. & Trauner, D. Controlling epithelial sodium channels with light using photoswitchable amilorides. Nat. Chem. 6, 712–719 (2014).

    Article  PubMed  CAS  Google Scholar 

  54. Fehrentz, T. et al. Optical control of L-type Ca(2+) channels using a diltiazem photoswitch. Nat. Chem. Biol. 14, 764–767 (2018).

    Article  CAS  PubMed  Google Scholar 

  55. Barber, D. M. et al. Optical control of neuronal activity using a light-operated GIRK channel opener (LOGO). Chem. Sci. 7, 2347–2352 (2016).

    Article  CAS  PubMed  Google Scholar 

  56. Leippe, P., Winter, N., Sumser, M. P. & Trauner, D. Optical control of a delayed rectifier and a two-pore potassium channel with a photoswitchable bupivacaine. ACS Chem. Neurosci. 9, 2886–2891 (2018).

    Article  CAS  PubMed  Google Scholar 

  57. Broichhagen, J. et al. Optical control of insulin release using a photoswitchable sulfonylurea. Nat. Commun. 5, 5116 (2014).

    Article  CAS  PubMed  Google Scholar 

  58. Stein, M., Breit, A., Fehrentz, T., Gudermann, T. & Trauner, D. Optical control of TRPV1 channels. Angew. Chem. Int. Ed. 52, 9845–9848 (2013).

    Article  CAS  Google Scholar 

  59. Stawski, P., Sumser, M. & Trauner, D. A photochromic agonist of AMPA receptors. Angew. Chem. Int. Ed. 51, 5748–5751 (2012).

    Article  CAS  Google Scholar 

  60. Laprell, L. et al. Optical control of NMDA receptors with a diffusible photoswitch. Nat. Commun. 6, 8076 (2015).

    Article  CAS  PubMed  Google Scholar 

  61. Laprell, L. et al. Restoring light sensitivity in blind retinae using a photochromic AMPA receptor agonist. ACS Chem. Neurosci. 7, 15–20 (2016).

    Article  CAS  PubMed  Google Scholar 

  62. Barber, D. M. et al. Optical control of AMPA receptors using a photoswitchable quinoxaline-2,3-dione antagonist. Chem. Sci. 8, 611–615 (2017).

    Article  CAS  PubMed  Google Scholar 

  63. Damijonaitis, A. et al. AzoCholine enables optical control of alpha 7 nicotinic acetylcholine receptors in neural networks. ACS Chem. Neurosci. 6, 701–707 (2015).

    Article  CAS  PubMed  Google Scholar 

  64. Bahamonde, M. I. et al. Photomodulation of G protein-coupled adenosine receptors by a novel light-switchable ligand. Bioconjug. Chem. 25, 1847–1854 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Huckvale, R., Mortensen, M., Pryde, D., Smart, T. G. & Baker, J. R. Azogabazine; a photochromic antagonist of the GABAA receptor. Org. Biomol. Chem. 14, 6676–6678 (2016).

    Article  CAS  PubMed  Google Scholar 

  66. Pittolo, S. et al. An allosteric modulator to control endogenous G protein-coupled receptors with light. Nat. Chem. Biol. 10, 813–815 (2014). This paper describes the first development of a light-controllable allosteric modulator for GPCRs, used to control locomotion in tadpoles.

    Article  CAS  PubMed  Google Scholar 

  67. Rovira, X. et al. OptoGluNAM4.1, a photoswitchable allosteric antagonist for real-time control of mGlu4 receptor activity. Cell Chem. Biol 23, 929–934 (2016).

    Article  CAS  PubMed  Google Scholar 

  68. Gomez-Santacana, X. et al. Illuminating phenylazopyridines to photoswitch metabotropic glutamate receptors: from the flask to the animals. ACS Cent. Sci. 3, 81–91 (2017).

    Article  CAS  PubMed  Google Scholar 

  69. Zussy, C. et al. Dynamic modulation of inflammatory pain-related affective and sensory symptoms by optical control of amygdala metabotropic glutamate receptor 4. Mol. Psychiatry 23, 509–520 (2018).

    Article  CAS  PubMed  Google Scholar 

  70. Bossi, S. et al. A light-controlled allosteric modulator unveils a role for mGlu4 receptors during early stages of ischemia in the rodent cerebellar cortex. Front. Cell. Neurosci. 12, 449 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  71. Stein, M. et al. Azo-propofols: photochromic potentiators of GABA(A) receptors. Angew. Chem. Int. Ed. 51, 10500–10504 (2012).

    Article  CAS  Google Scholar 

  72. Yue, L. et al. Robust photoregulation of GABA(A) receptors by allosteric modulation with a propofol analogue. Nat. Commun. 3, 1095 (2012).

    Article  PubMed  CAS  Google Scholar 

  73. Beharry, A. A. & Woolley, G. A. Azobenzene photoswitches for biomolecules. Chem. Soc. Rev. 40, 4422–4437 (2011).

    Article  CAS  PubMed  Google Scholar 

  74. Broichhagen, J., Frank, J. A. & Trauner, D. A roadmap to success in photopharmacology. Acc. Chem. Res. 48, 1947–1960 (2015).

    Article  CAS  PubMed  Google Scholar 

  75. Lin, W. C., Tsai, M. C., Rajappa, R. & Kramer, R. H. Design of a highly bistable photoswitchable tethered ligand for rapid and sustained manipulation of neurotransmission. J. Am. Chem. Soc. 140, 7445–7448 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Samanta, S., Qin, C., Lough, A. J. & Woolley, G. A. Bidirectional photocontrol of peptide conformation with a bridged azobenzene derivative. Angew. Chem. Int. Ed. 51, 6452–6455 (2012).

    Article  CAS  Google Scholar 

  77. Thapaliya, E. R., Zhao, J. & Ellis-Davies, G. C. R. Locked-azobenzene: testing the scope of a unique photoswitchable scaffold for cell physiology. ACS Chem. Neurosci. 10, 2481–2488 (2019).

    Article  CAS  PubMed  Google Scholar 

  78. Chi, L., Sadovski, O. & Woolley, G. A. A blue-green absorbing cross-linker for rapid photoswitching of peptide helix content. Bioconjug. Chem. 17, 670–676 (2006).

    Article  CAS  PubMed  Google Scholar 

  79. Samanta, S. et al. Photoswitching azo compounds in vivo with red light. J. Am. Chem. Soc. 135, 9777–9784 (2013).

    Article  CAS  PubMed  Google Scholar 

  80. Kienzler, M. A. et al. A red-shifted, fast-relaxing azobenzene photoswitch for visible light control of an ionotropic glutamate receptor. J. Am. Chem. Soc. 135, 17683–17686 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. Rullo, A. et al. Long wavelength optical control of glutamate receptor ion channels using a tetra-ortho-substituted azobenzene derivative. Chem. Commun. 50, 14613–14615 (2014).

    Article  CAS  Google Scholar 

  82. Hoppmann, C., Maslennikov, I., Choe, S. & Wang, L. In situ formation of an azo bridge on proteins controllable by visible light. J. Am. Chem. Soc. 137, 11218–11221 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  83. Dong, M., Babalhavaeji, A., Samanta, S., Beharry, A. A. & Woolley, G. A. Red-shifting azobenzene photoswitches for in vivo use. Acc. Chem. Res. 48, 2662–2670 (2015).

    Article  CAS  PubMed  Google Scholar 

  84. Dong, M. et al. Near-infrared photoswitching of azobenzenes under physiological conditions. J. Am. Chem. Soc. 139, 13483–13486 (2017).

    Article  CAS  PubMed  Google Scholar 

  85. Passlick, S., Richers, M. T. & Ellis-Davies, G. C. R. Thermodynamically stable, photoreversible pharmacology in neurons with one- and two-photon excitation. Angew. Chem. Int. Ed. 57, 12554–12557 (2018).

    Article  CAS  Google Scholar 

  86. Borowiak, M. et al. Photoswitchable inhibitors of microtubule dynamics optically control mitosis and cell death. Cell 162, 403–411 (2015).

    Article  CAS  PubMed  Google Scholar 

  87. Gorostiza, P. et al. Mechanisms of photoswitch conjugation and light activation of an ionotropic glutamate receptor. Proc. Natl Acad. Sci. USA 104, 10865–10870 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  88. Mourot, A., Tochitsky, I. & Kramer, R. H. Light at the end of the channel: optical manipulation of intrinsic neuronal excitability with chemical photoswitches. Front. Mol. Neurosci. 6, 5 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  89. Schoenberger, M., Damijonaitis, A., Zhang, Z., Nagel, D. & Trauner, D. Development of a new photochromic ion channel blocker via azologization of fomocaine. ACS Chem. Neurosci. 5, 514–518 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  90. Kocer, A., Walko, M., Meijberg, W. & Feringa, B. L. A light-actuated nanovalve derived from a channel protein. Science 309, 755–758 (2005).

    Article  CAS  PubMed  Google Scholar 

  91. Lachmann, D. et al. Photochromic dopamine receptor ligands based on dithienylethenes and fulgides. Chemistry 23, 13423–13434 (2017).

    Article  CAS  PubMed  Google Scholar 

  92. Ruiz, M. L. & Karpen, J. W. Single cyclic nucleotide-gated channels locked in different ligand-bound states. Nature 389, 389–392 (1997). This paper reports the clever use of PALs to trap channel receptors in partially liganded states. Single-channel recordings were used to correlate ligand binding to channel gating.

    Article  CAS  PubMed  Google Scholar 

  93. Adesnik, H., Nicoll, R. A. & England, P. M. Photoinactivation of native AMPA receptors reveals their real-time trafficking. Neuron 48, 977–985 (2005).

    Article  CAS  PubMed  Google Scholar 

  94. Mortensen, M. et al. Photo-antagonism of the GABAA receptor. Nat. Commun. 5, 4454 (2014).

    Article  CAS  PubMed  Google Scholar 

  95. Huber, T. & Sakmar, T. P. Chemical biology methods for investigating G protein-coupled receptor signaling. Chem. Biol. 21, 1224–1237 (2014).

    Article  CAS  PubMed  Google Scholar 

  96. Jay, D. G. Selective destruction of protein function by chromophore-assisted laser inactivation. Proc. Natl Acad. Sci. USA 85, 5454–5458 (1988).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  97. Sano, Y., Watanabe, W. & Matsunaga, S. Chromophore-assisted laser inactivation—towards a spatiotemporal-functional analysis of proteins, and the ablation of chromatin, organelle and cell function. J. Cell Sci. 127, 1621–1629 (2014).

    Article  CAS  PubMed  Google Scholar 

  98. Takemoto, K. et al. Optical inactivation of synaptic AMPA receptors erases fear memory. Nat. Biotechnol. 35, 38–47 (2017). This paper shows that precise inactivation of endogenous AMPARs at specific synapses using CALI affects memory formation.

    Article  CAS  PubMed  Google Scholar 

  99. Goglia, A. G. & Toettcher, J. E. A bright future: optogenetics to dissect the spatiotemporal control of cell behavior. Curr. Opin. Chem. Biol. 48, 106–113 (2018).

    Article  PubMed  CAS  PubMed Central  Google Scholar 

  100. Spangler, S. M. & Bruchas, M. R. Optogenetic approaches for dissecting neuromodulation and GPCR signaling in neural circuits. Curr. Opin. Pharmacol. 32, 56–70 (2017).

    Article  CAS  PubMed  Google Scholar 

  101. Kim, J. M. et al. Light-driven activation of beta 2-adrenergic receptor signaling by a chimeric rhodopsin containing the beta 2-adrenergic receptor cytoplasmic loops. Biochemistry 44, 2284–2292 (2005).

    Article  CAS  PubMed  Google Scholar 

  102. Airan, R. D., Thompson, K. R., Fenno, L. E., Bernstein, H. & Deisseroth, K. Temporally precise in vivo control of intracellular signalling. Nature 458, 1025–1029 (2009).

    Article  CAS  PubMed  Google Scholar 

  103. Siuda, E. R. et al. Optodynamic simulation of beta-adrenergic receptor signalling. Nat. Commun. 6, 8480 (2015).

    Article  CAS  PubMed  Google Scholar 

  104. Li, P. et al. Optogenetic activation of intracellular adenosine A2A receptor signaling in the hippocampus is sufficient to trigger CREB phosphorylation and impair memory. Mol. Psychiatry 20, 1339–1349 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  105. Barish, P. A. et al. Design and functional evaluation of an optically active mu-opioid receptor. Eur. J. Pharmacol. 705, 42–48 (2013).

    Article  CAS  PubMed  Google Scholar 

  106. Siuda, E. R. et al. Spatiotemporal control of opioid signaling and behavior. Neuron 86, 923–935 (2015). The authors of this paper developed an opioid receptor–rhodopsin chimera. Light was used to mimic opioid signalling at specific synapses and to manipulate mouse behaviour.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  107. van Wyk, M., Pielecka-Fortuna, J., Lowel, S. & Kleinlogel, S. Restoring the ON switch in blind retinas: opto-mGluR6, a next-generation, cell-tailored optogenetic tool. PLOS Biol. 13, e1002143 (2015).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  108. Gunaydin, L. A. et al. Natural neural projection dynamics underlying social behavior. Cell 157, 1535–1551 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  109. Oh, E., Maejima, T., Liu, C., Deneris, E. & Herlitze, S. Substitution of 5-HT1A receptor signaling by a light-activated G protein-coupled receptor. J. Biol. Chem. 285, 30825–30836 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  110. Spoida, K., Masseck, O. A., Deneris, E. S. & Herlitze, S. Gq/5-HT2c receptor signals activate a local GABAergic inhibitory feedback circuit to modulate serotonergic firing and anxiety in mice. Proc. Natl Acad. Sci. USA 111, 6479–6484 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  111. Masseck, O. A. et al. Vertebrate cone opsins enable sustained and highly sensitive rapid control of Gi/o signaling in anxiety circuitry. Neuron 81, 1263–1273 (2014).

    Article  CAS  PubMed  Google Scholar 

  112. Morri, M. et al. Optical functionalization of human Class A orphan G-protein-coupled receptors. Nat. Commun. 9, 1950 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  113. Rost, B. R., Schneider-Warme, F., Schmitz, D. & Hegemann, P. Optogenetic tools for subcellular applications in neuroscience. Neuron 96, 572–603 (2017).

    Article  CAS  PubMed  Google Scholar 

  114. Schmidt, D., Tillberg, P. W., Chen, F. & Boyden, E. S. A fully genetically encoded protein architecture for optical control of peptide ligand concentration. Nat. Commun. 5, 3019 (2014).

    Article  PubMed  CAS  Google Scholar 

  115. He, L. et al. Near-infrared photoactivatable control of Ca(2+) signaling and optogenetic immunomodulation. eLife 4, e10024 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  116. Ma, G. et al. Optogenetic control of voltage-gated calcium channels. Angew. Chem. Int. Ed. 57, 7019–7022 (2018).

    Article  CAS  Google Scholar 

  117. Wu, Y. I. et al. A genetically encoded photoactivatable Rac controls the motility of living cells. Nature 461, 104–108 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  118. Dietz, D. M. et al. Rac1 is essential in cocaine-induced structural plasticity of nucleus accumbens neurons. Nat. Neurosci. 15, 891–896 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  119. Hayashi-Takagi, A. et al. Labelling and optical erasure of synaptic memory traces in the motor cortex. Nature 525, 333–338 (2015). This article shows a direct link between synaptic plasticity (dendritic spine formation) and memory storage, using a light-controllable RHO-GTPase.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  120. O’Neill, P. R. & Gautam, N. Subcellular optogenetic inhibition of G proteins generates signaling gradients and cell migration. Mol. Biol. Cell 25, 2305–2314 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  121. Liu, Q. et al. A photoactivatable botulinum neurotoxin for inducible control of neurotransmission. Neuron 101, 863–875 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  122. Cosentino, C. et al. Optogenetics. Engineering of a light-gated potassium channel. Science 348, 707–710 (2015).

    Article  CAS  PubMed  Google Scholar 

  123. Grusch, M. et al. Spatio-temporally precise activation of engineered receptor tyrosine kinases by light. EMBO J. 33, 1713–1726 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  124. Chang, K. Y. et al. Light-inducible receptor tyrosine kinases that regulate neurotrophin signalling. Nat. Commun. 5, 4057 (2014).

    Article  CAS  PubMed  Google Scholar 

  125. Sinnen, B. L. et al. Optogenetic control of synaptic composition and function. Neuron 93, 646–660 (2017). This paper describes a novel optogenetic approach to alter the molecular content of synapses. Intriguingly, light-induced recruitment of AMPARs affected the frequency, but not the amplitude, of synaptic events.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  126. Tour, O., Meijer, R. M., Zacharias, D. A., Adams, S. R. & Tsien, R. Y. Genetically targeted chromophore-assisted light inactivation. Nat. Biotechnol. 21, 1505–1508 (2003).

    Article  CAS  PubMed  Google Scholar 

  127. Lin, J. Y. et al. Optogenetic inhibition of synaptic release with chromophore-assisted light inactivation (CALI). Neuron 79, 241–253 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  128. Noren, C. J., Anthony-Cahill, S. J., Griffith, M. C. & Schultz, P. G. A general method for site-specific incorporation of unnatural amino acids into proteins. Science 244, 182–188 (1989).

    Article  CAS  PubMed  Google Scholar 

  129. Liu, C. C. & Schultz, P. G. Adding new chemistries to the genetic code. Annu. Rev. Biochem. 79, 413–444 (2010).

    Article  CAS  PubMed  Google Scholar 

  130. Chin, J. W. Expanding and reprogramming the genetic code. Nature 550, 53–60 (2017).

    Article  CAS  PubMed  Google Scholar 

  131. Beene, D. L., Dougherty, D. A. & Lester, H. A. Unnatural amino acid mutagenesis in mapping ion channel function. Curr. Opin. Neurobiol. 13, 264–270 (2003).

    Article  CAS  PubMed  Google Scholar 

  132. Klippenstein, V., Mony, L. & Paoletti, P. Probing ion channel structure and function using light-sensitive amino acids. Trends Biochem. Sci. 43, 436–451 (2018).

    Article  CAS  PubMed  Google Scholar 

  133. Miller, J. C., Silverman, S. K., England, P. M., Dougherty, D. A. & Lester, H. A. Flash decaging of tyrosine sidechains in an ion channel. Neuron 20, 619–624 (1998).

    Article  CAS  PubMed  Google Scholar 

  134. Philipson, K. D., Gallivan, J. P., Brandt, G. S., Dougherty, D. A. & Lester, H. A. Incorporation of caged cysteine and caged tyrosine into a transmembrane segment of the nicotinic ACh receptor. Am. J. Physiol. Cell Physiol. 281, C195–C206 (2001).

    Article  CAS  PubMed  Google Scholar 

  135. Kang, J. Y. et al. In vivo expression of a light-activatable potassium channel using unnatural amino acids. Neuron 80, 358–370 (2013).

    Article  CAS  PubMed  Google Scholar 

  136. Banghart, M., Borges, K., Isacoff, E., Trauner, D. & Kramer, R. H. Light-activated ion channels for remote control of neuronal firing. Nat. Neurosci. 7, 1381–1386 (2004). This pioneering paper reports the first rational engineering of a light-controllable protein by installing a photoswitchable ligand onto a cysteine-substituted K + channel and the demonstration of optogenetic control of action potential firing in cultured neurons.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  137. Volgraf, M. et al. Allosteric control of an ionotropic glutamate receptor with an optical switch. Nat. Chem. Biol. 2, 47–52 (2006).

    Article  CAS  PubMed  Google Scholar 

  138. Broichhagen, J. et al. Orthogonal optical control of a G protein-coupled receptor with a SNAP-tethered photochromic ligand. ACS Cent. Sci. 1, 383–393 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  139. Levitz, J. et al. Dual optical control and mechanistic insights into photoswitchable group II and III metabotropic glutamate receptors. Proc. Natl Acad. Sci. USA 114, E3546–E3554 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  140. Farrants, H. et al. SNAP-tagged nanobodies enable reversible optical control of a G protein-coupled receptor via a remotely tethered photoswitchable ligand. ACS Chem. Biol. 13, 2682–2688 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  141. Browne, L. E. et al. Optical control of trimeric P2X receptors and acid-sensing ion channels. Proc. Natl Acad. Sci. USA 111, 521–526 (2014).

    Article  CAS  PubMed  Google Scholar 

  142. Habermacher, C. et al. Photo-switchable tweezers illuminate pore-opening motions of an ATP-gated P2X ion channel. eLife 5, e11050 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  143. Harkat, M. et al. On the permeation of large organic cations through the pore of ATP-gated P2X receptors. Proc. Natl Acad. Sci. USA 114, E3786–E3795 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  144. Fortin, D. L. et al. Optogenetic photochemical control of designer K+ channels in mammalian neurons. J. Neurophysiol. 106, 488–496 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  145. Sandoz, G., Levitz, J., Kramer, R. H. & Isacoff, E. Y. Optical control of endogenous proteins with a photoswitchable conditional subunit reveals a role for TREK1 in GABA(B) signaling. Neuron 74, 1005–1014 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  146. Levitz, J. et al. Optical control of metabotropic glutamate receptors. Nat. Neurosci. 16, 507–516 (2013). This paper documents the extension of the PTL technology to GPCRs — specifically, the engineering of agonized and antagonized versions of metabotropic glutamate receptors.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  147. Berlin, S. et al. A family of photoswitchable NMDA receptors. eLife 5, e12040 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  148. Tochitsky, I. et al. Optochemical control of genetically engineered neuronal nicotinic acetylcholine receptors. Nat. Chem. 4, 105–111 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  149. Lin, W. C. et al. Engineering a light-regulated GABAA receptor for optical control of neural inhibition. ACS Chem. Biol. 9, 1414–1419 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  150. Lin, W. C. et al. A comprehensive optogenetic pharmacology toolkit for in vivo control of GABA(A) receptors and synaptic inhibition. Neuron 88, 879–891 (2015). This paper documents the first use of the PTL technology in the brain of living mice and the first development of transgenic mice expressing a cysteine-substituted receptor for optopharmacology.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  151. Lemoine, D. et al. Optical control of an ion channel gate. Proc. Natl Acad. Sci. USA 110, 20813–20818 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  152. Donthamsetti, P. C. et al. Optical control of dopamine receptors using a photoswitchable tethered inverse agonist. J. Am. Chem. Soc. 139, 18522–18535 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  153. Reiner, A. & Isacoff, E. Y. Tethered ligands reveal glutamate receptor desensitization depends on subunit occupancy. Nat. Chem. Biol. 10, 273–280 (2014). This paper reports the clever use of the PTL technology to optically ‘clamp’ ligands in their binding pocket, to study the relationship between binding, gating and desensitization.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  154. Li, G. D. et al. Identification of a GABAA receptor anesthetic binding site at subunit interfaces by photolabeling with an etomidate analog. J. Neurosci. 26, 11599–11605 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  155. Yip, G. M. et al. A propofol binding site on mammalian GABAA receptors identified by photolabeling. Nat. Chem. Biol. 9, 715–720 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  156. Valentin-Hansen, L. et al. Mapping substance P binding sites on the neurokinin-1 receptor using genetic incorporation of a photoreactive amino acid. J. Biol. Chem. 289, 18045–18054 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  157. Coin, I. et al. Genetically encoded chemical probes in cells reveal the binding path of urocortin-I to CRF class B GPCR. Cell 155, 1258–1269 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  158. Simms, J. et al. Photoaffinity cross-linking and unnatural amino acid mutagenesis reveal insights into calcitonin gene-related peptide binding to the calcitonin receptor-like receptor/receptor activity-modifying protein 1 (CLR/RAMP1) complex. Biochemistry 57, 4915–4922 (2018).

    Article  CAS  PubMed  Google Scholar 

  159. Murray, C. I. et al. Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4. eLife 5, e11815 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  160. Westhoff, M., Murray, C. I., Eldstrom, J. & Fedida, D. Photo-cross-linking of IKs demonstrates state-dependent interactions between KCNE1 and KCNQ1. Biophys. J. 113, 415–425 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  161. Klippenstein, V., Ghisi, V., Wietstruk, M. & Plested, A. J. Photoinactivation of glutamate receptors by genetically encoded unnatural amino acids. J. Neurosci. 34, 980–991 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  162. Zhu, S. et al. Genetically encoding a light switch in an ionotropic glutamate receptor reveals subunit-specific interfaces. Proc. Natl Acad. Sci. USA 111, 6081–6086 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  163. Tian, M. & Ye, S. Allosteric regulation in NMDA receptors revealed by the genetically encoded photo-cross-linkers. Sci. Rep. 6, 34751 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  164. Klippenstein, V., Hoppmann, C., Ye, S., Wang, L. & Paoletti, P. Optocontrol of glutamate receptor activity by single side-chain photoisomerization. eLife 6, e25808 (2017). In this study, unnatural PSAAs were incorporated at key locations in NMDARs; robust photoregulation of receptor activity was observed upon subtle structural changes of the protein.

    Article  PubMed  PubMed Central  Google Scholar 

  165. Matsubara, N., Billington, A. P. & Hess, G. P. How fast does an acetylcholine receptor channel open? Laser-pulse photolysis of an inactive precursor of carbamoylcholine in the microsecond time region with BC3H1 cells. Biochemistry 31, 5507–5514 (1992).

    Article  CAS  PubMed  Google Scholar 

  166. DiGregorio, D. A., Rothman, J. S., Nielsen, T. A. & Silver, R. A. Desensitization properties of AMPA receptors at the cerebellar mossy fiber granule cell synapse. J. Neurosci. 27, 8344–8357 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  167. Levitz, J. et al. Mechanism of assembly and cooperativity of homomeric and heteromeric metabotropic glutamate receptors. Neuron 92, 143–159 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  168. Eder, M., Zieglgansberger, W. & Dodt, H. U. Shining light on neurons—elucidation of neuronal functions by photostimulation. Rev. Neurosci 15, 167–183 (2004).

    Article  PubMed  Google Scholar 

  169. Shepherd, G. M. Circuit mapping by ultraviolet uncaging of glutamate. Cold Spring Harb. Protoc 2012, 998–1004 (2012).

    Article  PubMed  PubMed Central  Google Scholar 

  170. Callaway, E. M. & Katz, L. C. Photostimulation using caged glutamate reveals functional circuitry in living brain slices. Proc. Natl Acad. Sci. USA 90, 7661–7665 (1993).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  171. Denk, W. Two-photon scanning photochemical microscopy: mapping ligand-gated ion channel distributions. Proc. Natl Acad. Sci. USA 91, 6629–6633 (1994).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  172. Khiroug, L., Giniatullin, R., Klein, R. C., Fayuk, D. & Yakel, J. L. Functional mapping and Ca2+ regulation of nicotinic acetylcholine receptor channels in rat hippocampal CA1 neurons. J. Neurosci. 23, 9024–9031 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  173. Ko, K. W., Rasband, M. N., Meseguer, V., Kramer, R. H. & Golding, N. L. Serotonin modulates spike probability in the axon initial segment through HCN channels. Nat. Neurosci. 19, 826–834 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  174. Patterson, M. A., Szatmari, E. M. & Yasuda, R. AMPA receptors are exocytosed in stimulated spines and adjacent dendrites in a Ras-ERK-dependent manner during long-term potentiation. Proc. Natl Acad. Sci. USA 107, 15951–15956 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  175. Lee, S. J., Escobedo-Lozoya, Y., Szatmari, E. M. & Yasuda, R. Activation of CaMKII in single dendritic spines during long-term potentiation. Nature 458, 299–304 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  176. Harvey, C. D., Yasuda, R., Zhong, H. & Svoboda, K. The spread of Ras activity triggered by activation of a single dendritic spine. Science 321, 136–140 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  177. Murakoshi, H., Wang, H. & Yasuda, R. Local, persistent activation of Rho GTPases during plasticity of single dendritic spines. Nature 472, 100–104 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  178. Hedrick, N. G. et al. Rho GTPase complementation underlies BDNF-dependent homo- and heterosynaptic plasticity. Nature 538, 104–108 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  179. Zhai, S., Ark, E. D., Parra-Bueno, P. & Yasuda, R. Long-distance integration of nuclear ERK signaling triggered by activation of a few dendritic spines. Science 342, 1107–1111 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  180. Yasuda, R. Biophysics of biochemical signaling in dendritic spines: implications in synaptic plasticity. Biophys. J. 113, 2152–2159 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  181. Schiller, J., Major, G., Koester, H. J. & Schiller, Y. NMDA spikes in basal dendrites of cortical pyramidal neurons. Nature 404, 285–289 (2000).

    Article  CAS  PubMed  Google Scholar 

  182. Losonczy, A. & Magee, J. C. Integrative properties of radial oblique dendrites in hippocampal CA1 pyramidal neurons. Neuron 50, 291–307 (2006).

    Article  CAS  PubMed  Google Scholar 

  183. Noguchi, J., Matsuzaki, M., Ellis-Davies, G. C. & Kasai, H. Spine-neck geometry determines NMDA receptor-dependent Ca2+ signaling in dendrites. Neuron 46, 609–622 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  184. Branco, T., Clark, B. A. & Hausser, M. Dendritic discrimination of temporal input sequences in cortical neurons. Science 329, 1671–1675 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  185. Rall, W., Burke, R. E., Smith, T. G., Nelson, P. G. & Frank, K. Dendritic location of synapses and possible mechanisms for the monosynaptic EPSP in motoneurons. J. Neurophysiol. 30, 1169–1193 (1967).

    Article  CAS  PubMed  Google Scholar 

  186. Kauwe, G. & Isacoff, E. Y. Rapid feedback regulation of synaptic efficacy during high-frequency activity at the Drosophila larval neuromuscular junction. Proc. Natl Acad. Sci. USA 110, 9142–9147 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  187. Li, D., Herault, K., Isacoff, E. Y., Oheim, M. & Ropert, N. Optogenetic activation of LiGluR-expressing astrocytes evokes anion channel-mediated glutamate release. J. Physiol 590, 855–873 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  188. Zhang, Y. P., Holbro, N. & Oertner, T. G. Optical induction of plasticity at single synapses reveals input-specific accumulation of alphaCaMKII. Proc. Natl Acad. Sci. USA 105, 12039–12044 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  189. Chiu, C. Q. et al. Compartmentalization of GABAergic inhibition by dendritic spines. Science 340, 759–762 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  190. Hayama, T. et al. GABA promotes the competitive selection of dendritic spines by controlling local Ca2+ signaling. Nat. Neurosci. 16, 1409–1416 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  191. Yagishita, S. et al. A critical time window for dopamine actions on the structural plasticity of dendritic spines. Science 345, 1616–1620 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  192. Olson, J. P. et al. Optically selective two-photon uncaging of glutamate at 900 nm. J. Am. Chem. Soc. 135, 5954–5957 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  193. Amatrudo, J. M. et al. Wavelength-selective one- and two-photon uncaging of GABA. ACS Chem. Neurosci. 5, 64–70 (2014).

    Article  CAS  PubMed  Google Scholar 

  194. Olson, J. P., Banghart, M. R., Sabatini, B. L. & Ellis-Davies, G. C. Spectral evolution of a photochemical protecting group for orthogonal two-color uncaging with visible light. J. Am. Chem. Soc. 135, 15948–15954 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  195. Agarwal, H. K., Zhai, S., Surmeier, D. J. & Ellis-Davies, G. C. R. Intracellular uncaging of cGMP with blue light. ACS Chem. Neurosci. 8, 2139–2144 (2017).

    Article  CAS  PubMed  Google Scholar 

  196. Amatrudo, J. M., Olson, J. P., Agarwal, H. K. & Ellis-Davies, G. C. Caged compounds for multichromic optical interrogation of neural systems. Eur. J. Neurosci. 41, 5–16 (2015).

    Article  PubMed  Google Scholar 

  197. Herrera, C. G. & Adamantidis, A. R. An integrated microprobe for the brain. Nat. Biotechnol. 33, 259–260 (2015).

    Article  CAS  PubMed  Google Scholar 

  198. Canales, A., Park, S., Kilias, A. & Anikeeva, P. Multifunctional fibers as tools for neuroscience and neuroengineering. Acc. Chem. Res. 51, 829–838 (2018).

    Article  CAS  PubMed  Google Scholar 

  199. Kokel, D. et al. Photochemical activation of TRPA1 channels in neurons and animals. Nat. Chem. Biol. 9, 257–263 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  200. Noguchi, J. et al. In vivo two-photon uncaging of glutamate revealing the structure-function relationships of dendritic spines in the neocortex of adult mice. J. Physiol 589, 2447–2457 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  201. Font, J. et al. Optical control of pain in vivo with a photoactive mGlu5 receptor negative allosteric modulator. eLife 6, e23545 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  202. Polosukhina, A. et al. Photochemical restoration of visual responses in blind mice. Neuron 75, 271–282 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  203. Tochitsky, I. et al. Restoring visual function to blind mice with a photoswitch that exploits electrophysiological remodeling of retinal ganglion cells. Neuron 81, 800–813 (2014). This paper demonstrates that vision can be restored in mice in which photoreceptors have degenerated, using a small diffusible photoswitch that operates with visible light.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  204. Tochitsky, I. et al. How azobenzene photoswitches restore visual responses to the blind retina. Neuron 92, 100–113 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  205. Tochitsky, I., Trautman, J., Gallerani, N., Malis, J. G. & Kramer, R. H. Restoring visual function to the blind retina with a potent, safe and long-lasting photoswitch. Sci. Rep. 7, 45487 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  206. Tochitsky, I., Kienzler, M. A., Isacoff, E. & Kramer, R. H. Restoring vision to the blind with chemical photoswitches. Chem. Rev. 118, 10748–10773 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  207. Trusel, M. et al. Punishment-predictive cues guide avoidance through potentiation of hypothalamus-to-habenula synapses. Neuron 102, 120–127 (2019).

    Article  CAS  PubMed  Google Scholar 

  208. Levitz, J., Popescu, A. T., Reiner, A. & Isacoff, E. Y. A. Toolkit for orthogonal and in vivo optical manipulation of ionotropic glutamate receptors. Front. Mol. Neurosci. 9, 2 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  209. Durand-de Cuttoli, R. et al. Manipulating midbrain dopamine neurons and reward-related behaviors with light-controllable nicotinic acetylcholine receptors. eLife 7, e37487 (2018). This paper describes the first demonstration of the PTL technology in freely behaving mice; the technology enabled reversible control of nicotinic transmission in mice in vivo.

    Article  PubMed  PubMed Central  Google Scholar 

  210. Szobota, S. et al. Remote control of neuronal activity with a light-gated glutamate receptor. Neuron 54, 535–545 (2007).

    Article  CAS  PubMed  Google Scholar 

  211. Wyart, C. et al. Optogenetic dissection of a behavioural module in the vertebrate spinal cord. Nature 461, 407–410 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  212. Janovjak, H., Szobota, S., Wyart, C., Trauner, D. & Isacoff, E. Y. A light-gated, potassium-selective glutamate receptor for the optical inhibition of neuronal firing. Nat. Neurosci. 13, 1027–1032 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  213. Caporale, N. et al. LiGluR restores visual responses in rodent models of inherited blindness. Mol. Ther. 19, 1212–1219 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  214. Gaub, B. M. et al. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells. Proc. Natl Acad. Sci. USA 111, E5574–E5583 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  215. Berry, M. H. et al. Restoration of patterned vision with an engineered photoactivatable G protein-coupled receptor. Nat. Commun. 8, 1862 (2017).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  216. Izquierdo-Serra, M. et al. Two-photon neuronal and astrocytic stimulation with azobenzene-based photoswitches. J. Am. Chem. Soc. 136, 8693–8701 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  217. Gascon-Moya, M. et al. An optimized glutamate receptor photoswitch with sensitized azobenzene isomerization. J. Org. Chem. 80, 9915–9925 (2015).

    Article  CAS  PubMed  Google Scholar 

  218. Carroll, E. C. et al. Two-photon brightness of azobenzene photoswitches designed for glutamate receptor optogenetics. Proc. Natl Acad. Sci. USA 112, E776–E785 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  219. Cabre, G. et al. Rationally designed azobenzene photoswitches for efficient two-photon neuronal excitation. Nat. Commun. 10, 907 (2019).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  220. Ernst, R. J. et al. Genetic code expansion in the mouse brain. Nat. Chem. Biol. 12, 776–778 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  221. Han, S. et al. Expanding the genetic code of Mus musculus. Nat. Commun. 8, 14568 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  222. Zheng, Y. et al. Virus-enabled optimization and delivery of the genetic machinery for efficient unnatural amino acid mutagenesis in mammalian cells and tissues. ACS Synth. Biol. 6, 13–18 (2017).

    Article  CAS  PubMed  Google Scholar 

  223. Chen, Y. et al. Heritable expansion of the genetic code in mouse and zebrafish. Cell Res. 27, 294–297 (2017).

    Article  CAS  PubMed  Google Scholar 

  224. Tufail, Y. et al. Transcranial pulsed ultrasound stimulates intact brain circuits. Neuron 66, 681–694 (2010).

    Article  CAS  PubMed  Google Scholar 

  225. Nimpf, S. & Keays, D. A. Is magnetogenetics the new optogenetics? EMBO J. 36, 1643–1646 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  226. Lerch, M. M., Hansen, M. J., van Dam, G. M., Szymanski, W. & Feringa, B. L. Emerging targets in photopharmacology. Angew. Chem. Int. Ed. 55, 10978–10999 (2016).

    Article  CAS  Google Scholar 

  227. Laprell, L. et al. Photopharmacological control of bipolar cells restores visual function in blind mice. J. Clin. Invest 127, 2598–2611 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  228. Roska, B. & Sahel, J. A. Restoring vision. Nature 557, 359–367 (2018).

    Article  CAS  PubMed  Google Scholar 

  229. US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT02556736 (2019).

  230. Basbaum, A. I., Bautista, D. M., Scherrer, G. & Julius, D. Cellular and molecular mechanisms of pain. Cell 139, 267–284 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  231. Frank, J. A. et al. Photoswitchable fatty acids enable optical control of TRPV1. Nat. Commun. 6, 7118 (2015).

    Article  PubMed  Google Scholar 

  232. Schonberger, M. & Trauner, D. A photochromic agonist for mu-opioid receptors. Angew. Chem. Int. Ed. 53, 3264–3267 (2014).

    Article  CAS  Google Scholar 

  233. Mourot, A., Herold, C., Kienzler, M. A. & Kramer, R. H. Understanding and improving photo-control of ion channels in nociceptors with azobenzene photo-switches. Br. J. Pharmacol. 175, 2296–2311 (2018).

    Article  CAS  PubMed  Google Scholar 

  234. Kim, T. I. et al. Injectable, cellular-scale optoelectronics with applications for wireless optogenetics. Science 340, 211–216 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  235. Montgomery, K. L. et al. Wirelessly powered, fully internal optogenetics for brain, spinal and peripheral circuits in mice. Nat. Methods 12, 969–974 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  236. Park, S. I. et al. Soft, stretchable, fully implantable miniaturized optoelectronic systems for wireless optogenetics. Nat. Biotechnol. 33, 1280–1286 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  237. Park, S. I. et al. Stretchable multichannel antennas in soft wireless optoelectronic implants for optogenetics. Proc. Natl Acad. Sci. USA 113, E8169–E8177 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  238. Shin, G. et al. Flexible near-field wireless optoelectronics as subdermal implants for broad applications in optogenetics. Neuron 93, 509–521 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  239. Jeong, J. W. et al. Wireless optofluidic systems for programmable in vivo pharmacology and optogenetics. Cell 162, 662–674 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

This work was supported by the French government (‘Investissements d’Avenir’ ANR-10-LABX-54 MEMOLIFE, ANR-11-IDEX-0001-02 PSL University and ANR-11-LABX-0011-01 to P.P.; ANR-JCJC 2014 to A.M.), the European Research Council (ERC Advanced Grant #693021 to P.P.), the Brain and Behavior Research Foundation (NARSAD Young Investigator Award to A.M.) and the US National Institutes of Health (grants #GM053395 and #NS069720 to G.C.R.E.-D.). A.M. was the recipient of a fundamental research prize from the Medisite Foundation for Neuroscience.

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All authors researched data for article, made substantial contributions to the discussion of content, wrote the article and reviewed or edited the manuscript before submission.

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Correspondence to Pierre Paoletti, Graham C. R. Ellis-Davies or Alexandre Mourot.

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Glossary

Chromophores

Molecular groups that are responsible for light absorbance (and thus the colour of the molecule).

Photo-isomerizing group

A molecular group that can be switched between two distinct cis and trans configurations, or isomers, with particular wavelengths of light.

Allosteric modulators

Modulators of the activity of enzymes and receptors that target a ligand-binding site distinct from that to which the substrate or agonist binds.

Quantum yield

The efficiency of a photochemical reaction with respect to the amount of light absorbed.

Bistability

In azobenzenes, the ability for the cis and trans isomers each to be stable under particular illumination conditions and over long periods of time (minutes to days).

Photostationary state

The steady state reached by a photochemical reaction under a given illumination condition. In photo-isomerization, the photostationary state is usually given as a ratio of cis to trans photo-isomers.

Azologization

The process by which an established pharmacological compound is converted into a photoswitchable one, through the introduction of an azobenzene moiety.

Singlet oxygen

A specific state of the diatomic oxygen molecule (O2) that is usually produced by light irradiation and that can cause photo-damage to nearby molecules.

Genetic code expansion

A methodology that allows the introduction of unnatural amino acids into a protein. It is usually based on the re-assignment of an engineered stop codon within the protein coding sequence.

Agonist deactivation kinetics

Current decay following agonist removal from a ligand-gated ion channel.

Directional selectivity

The ability of a neuron to respond differentially to the direction of the stimulus.

Gliotransmission

The transmission of a signalling molecule that is released from glial cells and that acts on nearby cells (such as neurons).

Topographic maps

Spatially organized representations of a sensory surface (for example, the retina or the skin) in the cortex or other brain areas.

ON and OFF responses

Depolarization (ON) or hyperpolarization (OFF) of bipolar cells in the retina in response to light.

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Paoletti, P., Ellis-Davies, G.C.R. & Mourot, A. Optical control of neuronal ion channels and receptors. Nat Rev Neurosci 20, 514–532 (2019). https://doi.org/10.1038/s41583-019-0197-2

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