Abstract

The amygdala plays key roles in fear and anxiety. Studies of the amygdala have largely focused on neuronal function and connectivity. Astrocytes functionally interact with neurons, but their role in the amygdala remains largely unknown. We show that astrocytes in the medial subdivision of the central amygdala (CeM) determine the synaptic and behavioral outputs of amygdala circuits. To investigate the role of astrocytes in amygdala-related behavior and identify the underlying synaptic mechanisms, we used exogenous or endogenous signaling to selectively activate CeM astrocytes. Astrocytes depressed excitatory synapses from basolateral amygdala via A1 adenosine receptor activation and enhanced inhibitory synapses from the lateral subdivision of the central amygdala via A2A receptor activation. Furthermore, astrocytic activation decreased the firing rate of CeM neurons and reduced fear expression in a fear-conditioning paradigm. Therefore, we conclude that astrocyte activity determines fear responses by selectively regulating specific synapses, which indicates that animal behavior results from the coordinated activity of neurons and astrocytes.

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References

  1. 1.

    Emotion circuits in the brain. Annu. Rev. Neurosci. 23, 155–184 (2000).

  2. 2.

    & Amygdala microcircuits controlling learned fear. Neuron 82, 966–980 (2014).

  3. 3.

    et al. Amygdala inhibitory circuits and the control of fear memory. Neuron 62, 757–771 (2009).

  4. 4.

    Neurons of the lateral and basolateral amygdaloid nuclei: a Golgi study in the rat. J. Comp. Neurol. 212, 293–312 (1982).

  5. 5.

    , & Topographic organization of neurons in the acoustic thalamus that project to the amygdala. J. Neurosci. 10, 1043–1054 (1990).

  6. 6.

    Cortical pathways to the mammalian amygdala. Prog. Neurobiol. 55, 257–332 (1998).

  7. 7.

    Cytoarchitecture of the central amygdaloid nucleus of the rat. J. Comp. Neurol. 208, 401–418 (1982).

  8. 8.

    , , & Different projections of the central amygdaloid nucleus mediate autonomic and behavioral correlates of conditioned fear. J. Neurosci. 8, 2517–2529 (1988).

  9. 9.

    et al. Midbrain circuits for defensive behaviour. Nature 534, 206–212 (2016).

  10. 10.

    et al. Experience-dependent modification of a central amygdala fear circuit. Nat. Neurosci. 16, 332–339 (2013).

  11. 11.

    et al. The paraventricular thalamus controls a central amygdala fear circuit. Nature 519, 455–459 (2015).

  12. 12.

    et al. Genetic dissection of an amygdala microcircuit that gates conditioned fear. Nature 468, 270–276 (2010).

  13. 13.

    et al. Encoding of conditioned fear in central amygdala inhibitory circuits. Nature 468, 277–282 (2010).

  14. 14.

    , & Synaptic correlates of fear extinction in the amygdala. Nat. Neurosci. 13, 489–494 (2010).

  15. 15.

    et al. Amygdala circuitry mediating reversible and bidirectional control of anxiety. Nature 471, 358–362 (2011).

  16. 16.

    et al. Oxytocin selectively gates fear responses through distinct outputs from the central amygdala. Science 333, 104–107 (2011).

  17. 17.

    et al. Gliotransmitters travel in time and space. Neuron 81, 728–739 (2014).

  18. 18.

    , , & Tripartite synapses: glia, the unacknowledged partner. Trends Neurosci. 22, 208–215 (1999).

  19. 19.

    et al. Glial biology in learning and cognition. Neuroscientist 20, 426–431 (2014).

  20. 20.

    , & Tripartite synapses: astrocytes process and control synaptic information. Trends Neurosci. 32, 421–431 (2009).

  21. 21.

    , , , & Synaptically released acetylcholine evokes Ca2+ elevations in astrocytes in hippocampal slices. J. Neurosci. 22, 2443–2450 (2002).

  22. 22.

    et al. Local Ca2+ detection and modulation of synaptic release by astrocytes. Nat. Neurosci. 14, 1276–1284 (2011).

  23. 23.

    , & Astrocyte Ca2+ signalling: an unexpected complexity. Nat. Rev. Neurosci. 15, 327–335 (2014).

  24. 24.

    , & Spontaneous astrocytic Ca2+ oscillations in situ drive NMDAR-mediated neuronal excitation. Nat. Neurosci. 4, 803–812 (2001).

  25. 25.

    , , & Long-term potentiation depends on release of D-serine from astrocytes. Nature 463, 232–236 (2010).

  26. 26.

    & Astrocytes potentiate transmitter release at single hippocampal synapses. Science 317, 1083–1086 (2007).

  27. 27.

    et al. Astrocytes are endogenous regulators of basal transmission at central synapses. Cell 146, 785–798 (2011).

  28. 28.

    , , , & Do stars govern our actions? Astrocyte involvement in rodent behavior. Trends Neurosci. 38, 535–549 (2015).

  29. 29.

    et al. Gq-DREADD selectively initiates glial glutamate release and inhibits cue-induced cocaine seeking. Biol. Psychiatry 78, 441–451 (2015).

  30. 30.

    et al. Acute cannabinoids impair working memory through astroglial CB1 receptor modulation of hippocampal LTD. Cell 148, 1039–1050 (2012).

  31. 31.

    et al. Astrocytic modulation of sleep homeostasis and cognitive consequences of sleep loss. Neuron 61, 213–219 (2009).

  32. 32.

    & Endocannabinoids mediate neuron-astrocyte communication. Neuron 57, 883–893 (2008).

  33. 33.

    , , , & Circuit-specific signaling in astrocyte-neuron networks in basal ganglia pathways. Science 349, 730–734 (2015).

  34. 34.

    & Astrocyte signaling controls spike timing-dependent depression at neocortical synapses. Nat. Neurosci. 15, 746–753 (2012).

  35. 35.

    et al. Short-term adaptation of conditioned fear responses through endocannabinoid signaling in the central amygdala. Neuropsychopharmacology 36, 652–663 (2011).

  36. 36.

    et al. Multiple mechanistically distinct modes of endocannabinoid mobilization at central amygdala glutamatergic synapses. Neuron 81, 1111–1125 (2014).

  37. 37.

    , & Hippocampal short- and long-term plasticity are not modulated by astrocyte Ca2+ signaling. Science 327, 1250–1254 (2010).

  38. 38.

    & Endocannabinoids potentiate synaptic transmission through stimulation of astrocytes. Neuron 68, 113–126 (2010).

  39. 39.

    , & Putative single quantum and single fibre excitatory postsynaptic currents show similar amplitude range and variability in rat hippocampal slices. Eur. J. Neurosci. 4, 113–117 (1992).

  40. 40.

    & Extracellular adenosine concentrations in hippocampal brain slices and the tonic inhibitory modulation of evoked excitatory responses. J. Pharmacol. Exp. Ther. 268, 537–545 (1994).

  41. 41.

    et al. Astrocytic purinergic signaling coordinates synaptic networks. Science 310, 113–116 (2005).

  42. 42.

    et al. Glia-derived D-serine controls NMDA receptor activity and synaptic memory. Cell 125, 775–784 (2006).

  43. 43.

    et al. Astrocytic IP3 Rs: contribution to Ca2+ signalling and hippocampal LTP. Glia 65, 502–513 (2017).

  44. 44.

    et al. Activity-dependent switch of GABAergic inhibition into glutamatergic excitation in astrocyte-neuron networks. eLife 5, e20362 (2016).

  45. 45.

    , , & GABAergic network activation of glial cells underlies hippocampal heterosynaptic depression. J. Neurosci. 26, 5370–5382 (2006).

  46. 46.

    & Astrocytes regulate cortical state switching in vivo. Proc. Natl. Acad. Sci. USA 113, E2675–E2684 (2016).

  47. 47.

    et al. Endocannabinoids induce lateral long-term potentiation of transmitter release by stimulation of gliotransmission. Cereb. Cortex 25, 3699–3712 (2015).

  48. 48.

    , , & Endocannabinoid signaling and synaptic function. Neuron 76, 70–81 (2012).

  49. 49.

    , , , & Endocannabinoid-mediated control of synaptic transmission. Physiol. Rev. 89, 309–380 (2009).

  50. 50.

    & Lateral regulation of synaptic transmission by astrocytes. Neuroscience 323, 62–66 (2016).

  51. 51.

    , , , & Increased mortality, hypoactivity, and hypoalgesia in cannabinoid CB1 receptor knockout mice. Proc. Natl. Acad. Sci. USA 96, 5780–5785 (1999).

  52. 52.

    , , , & Endothelin-1-induced arrhythmogenic Ca2+ signaling is abolished in atrial myocytes of inositol-1,4,5-trisphosphate (IP3)-receptor type 2-deficient mice. Circ. Res. 96, 1274–1281 (2005).

  53. 53.

    , , , & Temporal control of gene recombination in astrocytes by transgenic expression of the tamoxifen-inducible DNA recombinase variant CreERT2. Glia 54, 11–20 (2006).

  54. 54.

    , , , & Physiological properties of central amygdala neurons: species differences. Eur. J. Neurosci. 15, 545–552 (2002).

  55. 55.

    , , & Bidirectional modulation of GABA release by presynaptic glutamate receptor 5 kainate receptors in the basolateral amygdala. J. Neurosci. 23, 442–452 (2003).

  56. 56.

    , , , & Structural and functional plasticity of astrocyte processes and dendritic spine interactions. J. Neurosci. 34, 12738–12744 (2014).

  57. 57.

    , & Confocal microscopy for astrocyte in vivo imaging: recycle and reuse in microscopy. Front. Cell. Neurosci. 7, 51 (2013).

  58. 58.

    et al. Specific in vivo staining of astrocytes in the whole brain after intravenous injection of sulforhodamine dyes. PLoS One 7, e35169 (2012).

  59. 59.

    & Unspecific labelling of oligodendrocytes by sulforhodamine 101 depends on astrocytic uptake via the thyroid hormone transporter OATP1C1 (SLCO1C1). Neurosci. Lett. 631, 13–18 (2016).

  60. 60.

    , & Identification of neuronal nuclei (NeuN) as Fox-3, a new member of the Fox-1 gene family of splicing factors. J. Biol. Chem. 284, 31052–31061 (2009).

  61. 61.

    et al. Toll-like receptors modulate adult hippocampal neurogenesis. Nat. Cell Biol. 9, 1081–1088 (2007).

  62. 62.

    , , , & A novel gene iba1 in the major histocompatibility complex class III region encoding an EF hand protein expressed in a monocytic lineage. Biochem. Biophys. Res. Commun. 224, 855–862 (1996).

  63. 63.

    et al. Expression of the APC tumor suppressor protein in oligodendroglia. Glia 17, 169–174 (1996).

  64. 64.

    & Endogenous cannabinoids mediate retrograde signalling at hippocampal synapses. Nature 410, 588–592 (2001).

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Acknowledgements

We thank J. Chen (UCSD, La Jolla, California, USA) for providing IP3R2 mice, and W. Buño, G. Perea, M. Navarrete and A. Covelo for helpful comments. This work was supported by NIH–NINDS (R01NS097312-01 to A.A.), the Human Frontier Science Program (Research Grant RGP0036/2014 to A.A. and G.M.), INSERM (to G.M.), Fondation pour la Recherche Medicale (DRM20101220445 to G.M.) and the China Scholarship Council (to Z.Z.). We thank the MnDRIVE Optogenetics Core at the University of Minnesota for technical support, and B. Roth and the UNC Vector Core (Chapel Hill, North Carolina, USA) for providing the Gq-DREADD adeno-associated virus.

Author information

Affiliations

  1. Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA.

    • Mario Martin-Fernandez
    • , Stephanie Jamison
    •  & Alfonso Araque
  2. INSERM, U1215 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France.

    • Laurie M Robin
    • , Zhe Zhao
    •  & Giovanni Marsicano
  3. Université de Bordeaux, Bordeaux, France.

    • Laurie M Robin
    • , Zhe Zhao
    •  & Giovanni Marsicano
  4. Instituto Cajal, Consejo Superior de Investigaciones Científicas. Madrid, Spain.

    • Eduardo D Martin
  5. Hospital Nacional de Parapléjicos, Servicio de Salud de Castilla–La Mancha, Toledo, Spain.

    • Juan Aguilar
  6. Mouse Behavior Core, University of Minnesota, Minneapolis, Minnesota, USA.

    • Michael A Benneyworth

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Contributions

M.M.-F. and A.A. conceived the study. M.M.-F., J.A., G.M. and A.A. wrote the manuscript. M.M.-F. performed and analyzed electrophysiological and calcium imaging experiments and analyzed the data. M.M.-F., E.D.M., J.A. and A.A. designed in vivo electrophysiological experiments. S.J. performed immunohistochemistry techniques. M.M.-F., M.A.B., G.M. and A.A. designed the behavioral experiments. M.A.B., L.M.R. and Z.Z. performed behavioral experiments. All the authors read and edited the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Alfonso Araque.

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https://doi.org/10.1038/nn.4649

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