Letter | Published:

Neural substrates of awakening probed with optogenetic control of hypocretin neurons

Nature volume 450, pages 420424 (15 November 2007) | Download Citation


The neural underpinnings of sleep involve interactions between sleep-promoting areas such as the anterior hypothalamus, and arousal systems located in the posterior hypothalamus, the basal forebrain and the brainstem1,2. Hypocretin3 (Hcrt, also known as orexin4)-producing neurons in the lateral hypothalamus5 are important for arousal stability2, and loss of Hcrt function has been linked to narcolepsy6,7,8,9. However, it is unknown whether electrical activity arising from Hcrt neurons is sufficient to drive awakening from sleep states or is simply correlated with it. Here we directly probed the impact of Hcrt neuron activity on sleep state transitions with in vivo neural photostimulation10,11,12,13,14,15,16,17,18, genetically targeting channelrhodopsin-2 to Hcrt cells and using an optical fibre to deliver light deep in the brain, directly into the lateral hypothalamus, of freely moving mice. We found that direct, selective, optogenetic photostimulation of Hcrt neurons increased the probability of transition to wakefulness from either slow wave sleep or rapid eye movement sleep. Notably, photostimulation using 5–30 Hz light pulse trains reduced latency to wakefulness, whereas 1 Hz trains did not. This study establishes a causal relationship between frequency-dependent activity of a genetically defined neural cell type and a specific mammalian behaviour central to clinical conditions and neurobehavioural physiology.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    & The neurobiology of sleep: genetics, cellular physiology and subcortical networks. Nature Rev. Neurosci. 3, 591–605 (2002)

  2. 2.

    , & The sleep switch: hypothalamic control of sleep and wakefulness. Trends Neurosci. 24, 726–731 (2001)

  3. 3.

    et al. The hypocretins: hypothalamus-specific peptides with neuroexcitatory activity. Proc. Natl Acad. Sci. USA 95, 322–327 (1998)

  4. 4.

    et al. Orexins and orexin receptors: a family of hypothalamic neuropeptides and G protein-coupled receptors that regulate feeding behavior. Cell 92, 573–585 (1998)

  5. 5.

    et al. Neurons containing hypocretin (orexin) project to multiple neuronal systems. J. Neurosci. 18, 9996–10015 (1998)

  6. 6.

    et al. Narcolepsy in orexin knockout mice: molecular genetics of sleep regulation. Cell 98, 437–451 (1999)

  7. 7.

    et al. The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin (orexin) receptor 2 gene. Cell 98, 365–376 (1999)

  8. 8.

    et al. A mutation in a case of early onset narcolepsy and a generalized absence of hypocretin peptides in human narcoleptic brains. Nature Med. 6, 991–997 (2000)

  9. 9.

    et al. Reduced number of hypocretin neurons in human narcolepsy. Neuron 27, 469–474 (2000)

  10. 10.

    , , , & Millisecond-timescale, genetically targeted optical control of neural activity. Nature Neurosci. 8, 1263–1268 (2005)

  11. 11.

    et al. Light activation of channelrhodopsin-2 in excitable cells of Caenorhabditis elegans triggers rapid behavioral responses. Curr. Biol. 15, 2279–2284 (2005)

  12. 12.

    , , & Channelrhodopsin-2 and optical control of excitable cells. Nature Methods 3, 785–792 (2006)

  13. 13.

    & Remote control of behavior through genetically targeted photostimulation of neurons. Cell 121, 141–152 (2005)

  14. 14.

    et al. An optical neural interface: In vivo control of rodent motor cortex with integrated fiberoptic and optogenetic technology. J. Neural Eng. 4, S143–S156 (2007)

  15. 15.

    , , & Channelrhodopsin-2-assisted circuit mapping of long-range callosal projections. Nature Neurosci. 10, 663–668 (2007)

  16. 16.

    et al. In vivo light-induced activation of neural circuitry in transgenic mice expressing channelrhodopsin-2. Neuron 54, 205–218 (2007)

  17. 17.

    et al. High-speed mapping of synaptic connectivity using photostimulation in Channelrhodopsin-2 transgenic mice. Proc. Natl Acad. Sci. USA 104, 8143–8148 (2007)

  18. 18.

    et al. Ectopic expression of a microbial-type rhodopsin restores visual responses in mice with photoreceptor degeneration. Neuron 50, 23–33 (2006)

  19. 19.

    et al. Transgenic mice with a reduced core body temperature have an increased life span. Science 314, 825–828 (2006)

  20. 20.

    et al. Structure and function of human prepro-orexin gene. J. Biol. Chem. 274, 17771–17776 (1999)

  21. 21.

    , , & Hypocretin/Orexin excites hypocretin neurons via a local glutamate neuron-A potential mechanism for orchestrating the hypothalamic arousal system. Neuron 36, 1169–1181 (2002)

  22. 22.

    , & Discharge of identified orexin/hypocretin neurons across the sleep–waking cycle. J. Neurosci. 25, 6716–6720 (2005)

  23. 23.

    , & Behavioral correlates of activity in identified hypocretin/orexin neurons. Neuron 46, 787–798 (2005)

  24. 24.

    et al. SB-334867-A: the first selective orexin-1 receptor antagonist. Br. J. Pharmacol. 132, 1179–1182 (2001)

  25. 25.

    et al. Multimodal fast optical interrogation of neural circuitry. Nature 446, 633–639 (2007)

  26. 26.

    & The Mouse Brain in Stereotaxic Coordinates 2nd edn (Academic, New York, 2001)

  27. 27.

    , , , & Stereotaxic gene delivery in the rodent brain. Nature Protocols 1, 3166–3173 (2006)

  28. 28.

    et al. Hypocretin-1 modulates rapid eye movement sleep through activation of locus coeruleus neurons. J. Neurosci. 20, 7760–7765 (2000)

  29. 29.

    et al. The wake-promoting hypocretin-orexin neurons are in an intrinsic state of membrane depolarization. J. Neurosci. 23, 1557–1562 (2003)

Download references


We thank S. Nishino and N. Fujiki for their technical support in sleep recording (Stanford University SCORE facility), and Y. Xu and C. E. Olin for critical comments. We also thank T. Sakurai and M. Yanagisawa for providing the Hcrt::EGFP transgenic and Hcrt knockout mice. A.R.A. is supported by the Belgian American Educational Foundation and the Fondation Leon Fredericq. F.Z. is supported by a fellowship from the NIH. A.M.A. is supported by the Walter and Idun Berry Foundation. K.D. is supported by NARSAD, APIRE and the Snyder, Culpeper, Coulter, Klingenstein, Whitehall, McKnight and Albert Yu and Mary Bechmann Foundations, as well as by NIMH, NIDA and the NIH Director’s Pioneer Award Program. L.dL. is supported by NIMH and NIDA.

Author Contributions All authors designed the experiments. A.R.A., F.Z. and A.M.A. collected data and performed analysis. All authors discussed the results and contributed to the text.

Author information

Author notes

    • Antoine R. Adamantidis
    •  & Feng Zhang

    These authors contributed equally to this work.


  1. Department of Psychiatry and Behavioral Sciences, Stanford University, 701B Welch Road, Palo Alto, California 94304, USA

    • Antoine R. Adamantidis
    • , Karl Deisseroth
    •  & Luis de Lecea
  2. Department of Bioengineering, Stanford University, James H. Clark Center W083, Stanford, California 94305, USA

    • Feng Zhang
    • , Alexander M. Aravanis
    •  & Karl Deisseroth


  1. Search for Antoine R. Adamantidis in:

  2. Search for Feng Zhang in:

  3. Search for Alexander M. Aravanis in:

  4. Search for Karl Deisseroth in:

  5. Search for Luis de Lecea in:

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Karl Deisseroth or Luis de Lecea.

Supplementary information

PDF files

  1. 1.

    Supplementary Information 1

    The file contains Supplementary Figures S1-S3 and Supplementary Tables 1-2 with Legends.


  1. 1.

    Supplementary Information 2

    The file contains Supplementary Video 1 showing recording of a SWS to wake transition after a single light pulse train with simultaneous EEG/EMG recordings (in inset).

  2. 2.

    Supplementary Information 3

    The file contains Supplementary Video 2 showing recording of a REM sleep to wake transition after a single light pulse train with simultaneous EEG/EMG recordings (in inset).

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.