Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Activation of cortical somatostatin interneurons prevents the development of neuropathic pain

Nature Neuroscience volume 20, pages 1122–1132 (2017)Cite this article

Subjects

Abstract

Neuropathic pain involves long-lasting modifications of pain pathways that result in abnormal cortical activity. How cortical circuits are altered and contribute to the intense sensation associated with allodynia is unclear. Here we report a persistent elevation of layer V pyramidal neuron activity in the somatosensory cortex of a mouse model of neuropathic pain. This enhanced pyramidal neuron activity was caused in part by increases of synaptic activity and NMDA-receptor-dependent calcium spikes in apical tuft dendrites. Furthermore, local inhibitory interneuron networks shifted their activity in favor of pyramidal neuron hyperactivity: somatostatin-expressing and parvalbumin-expressing inhibitory neurons reduced their activity, whereas vasoactive intestinal polypeptide–expressing interneurons increased their activity. Pharmacogenetic activation of somatostatin-expressing cells reduced pyramidal neuron hyperactivity and reversed mechanical allodynia. These findings reveal cortical circuit changes that arise during the development of neuropathic pain and identify the activation of specific cortical interneurons as therapeutic targets for chronic pain treatment.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Elevated L5 pyramidal somatic Ca2+ activity in S1 after peripheral nerve injury.
Figure 2: Enhanced dendritic spine and branch activity in S1 of neuropathic pain mice.
Figure 3: Elevated dendritic Ca2+ spike generation in apical tuft branches and trunks of L5 pyramidal neurons in S1 of neuropathic pain mice.
Figure 4: Alterations in inhibitory neuronal Ca2+ activity in S1 of neuropathic pain mice.
Figure 5: Acute activation of SOM neurons in S1 reduces L5 pyramidal neuron activity in mice with neuropathic pain.
Figure 6: Daily activation of SOM neurons following peripheral nerve injury prevents the development of neuropathic pain.

Similar content being viewed by others

References

  1. Baron, R. Mechanisms of disease: neuropathic pain—a clinical perspective. Nat. Clin. Pract. Neurol. 2, 95–106 (2006).

    Article  PubMed  Google Scholar 

  2. Costigan, M., Scholz, J. & Woolf, C.J. Neuropathic pain: a maladaptive response of the nervous system to damage. Annu. Rev. Neurosci. 32, 1–32 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. 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 

  4. Kuner, R. Central mechanisms of pathological pain. Nat. Med. 16, 1258–1266 (2010).

    Article  CAS  PubMed  Google Scholar 

  5. Saab, C.Y. Pain-related changes in the brain: diagnostic and therapeutic potentials. Trends Neurosci. 35, 629–637 (2012).

    Article  CAS  PubMed  Google Scholar 

  6. Bushnell, M.C., Ceko, M. & Low, L.A. Cognitive and emotional control of pain and its disruption in chronic pain. Nat. Rev. Neurosci. 14, 502–511 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Bushnell, M.C. et al. Pain perception: is there a role for primary somatosensory cortex? Proc. Natl. Acad. Sci. USA 96, 7705–7709 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Gross, J., Schnitzler, A., Timmermann, L. & Ploner, M. Gamma oscillations in human primary somatosensory cortex reflect pain perception. PLoS Biol. 5, e133 (2007).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  9. Seifert, F. & Maihöfner, C. Central mechanisms of experimental and chronic neuropathic pain: findings from functional imaging studies. Cell. Mol. Life Sci. 66, 375–390 (2009).

    Article  CAS  PubMed  Google Scholar 

  10. Peyron, R. et al. An fMRI study of cortical representation of mechanical allodynia in patients with neuropathic pain. Neurology 63, 1838–1846 (2004).

    Article  CAS  PubMed  Google Scholar 

  11. Seminowicz, D.A. et al. MRI structural brain changes associated with sensory and emotional function in a rat model of long-term neuropathic pain. Neuroimage 47, 1007–1014 (2009).

    Article  PubMed  Google Scholar 

  12. Flor, H., Denke, C., Schaefer, M. & Grüsser, S. Effect of sensory discrimination training on cortical reorganisation and phantom limb pain. Lancet 357, 1763–1764 (2001).

    Article  CAS  PubMed  Google Scholar 

  13. Lotze, M. et al. Does use of a myoelectric prosthesis prevent cortical reorganization and phantom limb pain? Nat. Neurosci. 2, 501–502 (1999).

    Article  CAS  PubMed  Google Scholar 

  14. De Ridder, D., De Mulder, G., Menovsky, T., Sunaert, S. & Kovacs, S. Electrical stimulation of auditory and somatosensory cortices for treatment of tinnitus and pain. Prog. Brain Res. 166, 377–388 (2007).

    Article  CAS  PubMed  Google Scholar 

  15. Kim, S.K. & Nabekura, J. Rapid synaptic remodeling in the adult somatosensory cortex following peripheral nerve injury and its association with neuropathic pain. J. Neurosci. 31, 5477–5482 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Eto, K. et al. Inter-regional contribution of enhanced activity of the primary somatosensory cortex to the anterior cingulate cortex accelerates chronic pain behavior. J. Neurosci. 31, 7631–7636 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Li, X.Y. et al. Alleviating neuropathic pain hypersensitivity by inhibiting PKMζ in the anterior cingulate cortex. Science 330, 1400–1404 (2010).

    Article  CAS  PubMed  Google Scholar 

  18. Blom, S.M., Pfister, J.P., Santello, M., Senn, W. & Nevian, T. Nerve injury-induced neuropathic pain causes disinhibition of the anterior cingulate cortex. J. Neurosci. 34, 5754–5764 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  19. Santello, M. & Nevian, T. Dysfunction of cortical dendritic integration in neuropathic pain reversed by serotoninergic neuromodulation. Neuron 86, 233–246 (2015).

    Article  CAS  PubMed  Google Scholar 

  20. Kim, S.K. et al. Cortical astrocytes rewire somatosensory cortical circuits for peripheral neuropathic pain. J. Clin. Invest. 126, 1983–1997 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  21. Eto, K. et al. Enhanced GABAergic activity in the mouse primary somatosensory cortex is insufficient to alleviate chronic pain behavior with reduced expression of neuronal potassium-chloride cotransporter. J. Neurosci. 32, 16552–16559 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. DeFelipe, J. et al. New insights into the classification and nomenclature of cortical GABAergic interneurons. Nat. Rev. Neurosci. 14, 202–216 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Decosterd, I. & Woolf, C.J. Spared nerve injury: an animal model of persistent peripheral neuropathic pain. Pain 87, 149–158 (2000).

    Article  CAS  PubMed  Google Scholar 

  24. Bourquin, A.F. et al. Assessment and analysis of mechanical allodynia-like behavior induced by spared nerve injury (SNI) in the mouse. Pain 122, 14.e1–14.e14 (2006).

    Article  Google Scholar 

  25. Harris, K.D. & Mrsic-Flogel, T.D. Cortical connectivity and sensory coding. Nature 503, 51–58 (2013).

    Article  CAS  PubMed  Google Scholar 

  26. Xu, N.L. et al. Nonlinear dendritic integration of sensory and motor input during an active sensing task. Nature 492, 247–251 (2012).

    Article  CAS  PubMed  Google Scholar 

  27. Cichon, J. & Gan, W.B. Branch-specific dendritic Ca2+ spikes cause persistent synaptic plasticity. Nature 520, 180–185 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Larkum, M.E., Nevian, T., Sandler, M., Polsky, A. & Schiller, J. Synaptic integration in tuft dendrites of layer 5 pyramidal neurons: a new unifying principle. Science 325, 756–760 (2009).

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Marlin, J.J. & Carter, A.G. GABA-A receptor inhibition of local calcium signaling in spines and dendrites. J. Neurosci. 34, 15898–15911 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  31. Muñoz, W., Tremblay, R., Levenstein, D. & Rudy, B. Layer-specific modulation of neocortical dendritic inhibition during active wakefulness. Science 355, 954–959 (2017).

    Article  PubMed  CAS  Google Scholar 

  32. Pi, H.J. et al. Cortical interneurons that specialize in disinhibitory control. Nature 503, 521–524 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Urban, D.J. & Roth, B.L. DREADDs (designer receptors exclusively activated by designer drugs): chemogenetic tools with therapeutic utility. Annu. Rev. Pharmacol. Toxicol. 55, 399–417 (2015).

    Article  CAS  PubMed  Google Scholar 

  34. Alexander, G.M. et al. Remote control of neuronal activity in transgenic mice expressing evolved G protein-coupled receptors. Neuron 63, 27–39 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Constantinople, C.M. & Bruno, R.M. Deep cortical layers are activated directly by thalamus. Science 340, 1591–1594 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. King, T. et al. Unmasking the tonic-aversive state in neuropathic pain. Nat. Neurosci. 12, 1364–1366 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Navratilova, E. et al. Pain relief produces negative reinforcement through activation of mesolimbic reward-valuation circuitry. Proc. Natl. Acad. Sci. USA 109, 20709–20713 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Golding, N.L., Staff, N.P. & Spruston, N. Dendritic spikes as a mechanism for cooperative long-term potentiation. Nature 418, 326–331 (2002).

    Article  CAS  PubMed  Google Scholar 

  39. Remy, S. & Spruston, N. Dendritic spikes induce single-burst long-term potentiation. Proc. Natl. Acad. Sci. USA 104, 17192–17197 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Palmer, L.M. et al. NMDA spikes enhance action potential generation during sensory input. Nat. Neurosci. 17, 383–390 (2014).

    Article  CAS  PubMed  Google Scholar 

  41. Knabl, J. et al. Reversal of pathological pain through specific spinal GABAA receptor subtypes. Nature 451, 330–334 (2008).

    Article  CAS  PubMed  Google Scholar 

  42. Coull, J.A.M. et al. Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic pain. Nature 424, 938–942 (2003).

    Article  CAS  PubMed  Google Scholar 

  43. Pfeffer, C.K., Xue, M., He, M., Huang, Z.J. & Scanziani, M. Inhibition of inhibition in visual cortex: the logic of connections between molecularly distinct interneurons. Nat. Neurosci. 16, 1068–1076 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Fu, Y. et al. A cortical circuit for gain control by behavioral state. Cell 156, 1139–1152 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Beierlein, M., Gibson, J.R. & Connors, B.W. Two dynamically distinct inhibitory networks in layer 4 of the neocortex. J. Neurophysiol. 90, 2987–3000 (2003).

    Article  PubMed  Google Scholar 

  46. Urban-Ciecko, J. & Barth, A.L. Somatostatin-expressing neurons in cortical networks. Nat. Rev. Neurosci. 17, 401–409 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Murphy, S.C., Palmer, L.M., Nyffeler, T., Müri, R.M. & Larkum, M.E. Transcranial magnetic stimulation (TMS) inhibits cortical dendrites. Elife 5, e13598 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  48. Lin, L.C. & Sibille, E. Reduced brain somatostatin in mood disorders: a common pathophysiological substrate and drug target? Front. Pharmacol. 4, 110 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  49. Hunt, R.F., Girskis, K.M., Rubenstein, J.L., Alvarez-Buylla, A. & Baraban, S.C. GABA progenitors grafted into the adult epileptic brain control seizures and abnormal behavior. Nat. Neurosci. 16, 692–697 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Dobolyi, A. et al. Receptors of peptides as therapeutic targets in epilepsy research. Curr. Med. Chem. 21, 764–787 (2014).

    Article  CAS  PubMed  Google Scholar 

  51. Yang, G., Pan, F., Chang, P.C., Gooden, F. & Gan, W.B. Transcranial two-photon imaging of synaptic structures in the cortex of awake head-restrained mice. Methods Mol. Biol. 1010, 35–43 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Dana, H. et al. Thy1-GCaMP6 transgenic mice for neuronal population imaging in vivo. PLoS One 9, e108697 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  53. Chen, T.W. et al. Ultrasensitive fluorescent proteins for imaging neuronal activity. Nature 499, 295–300 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Chagnac-Amitai, Y., Luhmann, H.J. & Prince, D.A. Burst generating and regular spiking layer 5 pyramidal neurons of rat neocortex have different morphological features. J. Comp. Neurol. 296, 598–613 (1990).

    Article  CAS  PubMed  Google Scholar 

  55. Agmon, A. & Connors, B.W. Correlation between intrinsic firing patterns and thalamocortical synaptic responses of neurons in mouse barrel cortex. J. Neurosci. 12, 319–329 (1992).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Smith, S.L., Smith, I.T., Branco, T. & Häusser, M. Dendritic spikes enhance stimulus selectivity in cortical neurons in vivo. Nature 503, 115–120 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank A. Sideris and B. Piskoun for surgical assistance and M. Santello, E. Recio-Pinto and J. Wang for discussions. We thank L. Looger (Janelia Farm Research Campus), the Genetically-Encoded Neuronal Indicator and Effector (GENIE) Project and the Janelia Farm Research Campus of the Howard Hughes Medical Institute for sharing GCaMP6 constructs. This work was supported by the Ralph S. French Charitable Foundation Trust (G.Y.), National Institutes of Health grants R01 GM107469 (G.Y.), R21 AG048410 (G.Y.), R01 NS047325 (W.-B.G.), R01 MH111486 (W.-B.G.) and U01 NS094341 (W.-B.G.).

Author information

Authors and Affiliations

  1. Department of Neuroscience and Physiology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, USA

    Joseph Cichon & Wen-Biao Gan

  2. Neuroscience Institute, New York University School of Medicine, New York, New York, USA

    Joseph Cichon, Wen-Biao Gan & Guang Yang

  3. Medical Scientist Training Program, New York University School of Medicine, New York, New York, USA

    Joseph Cichon

  4. Department of Anesthesiology, Perioperative Care and Pain Medicine, New York University School of Medicine, New York, New York, USA

    Thomas J J Blanck & Guang Yang

Authors
  1. Joseph Cichon
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Thomas J J Blanck
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Wen-Biao Gan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Guang Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

J.C., T.J.J.B., W.-B.G. and G.Y. designed the experiments. J.C. and G.Y. performed the experiments, J.C. analyzed the data. All of authors contributed to data interpretation. J.C., W.-B.G. and G.Y. wrote the manuscript.

Corresponding author

Correspondence to Guang Yang.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Integrated supplementary information

Supplementary Figure 1 Persistent elevation of L5 somatic Ca2+ activity in S1 after peripheral nerve injury.

(a) Representative two-photon images of active L5 pyramidal (PYR) neuron expressing GCaMP6s in SNI mice 1 month after surgery. Yellow arrowheads point to somata. Scale bar, 10 μm. (b) Average total integrated Ca2+ activity over 2.5 min in L5 PYR somata 1 month after surgery (SNI: n = 141 cells from 5 mice; Sham: n = 59 cells from 5 mice; t246 = 10.14, P < 0.001). Intraperitoneal (IP) injection of MK801 significantly reduced the activity of L5 PYR neurons in SNI (n = 29 cells from 2 mice; t246 = 9.681, P < 0.001) but not in sham mice (n = 21 cells from 2 mice; t246 = 0.9972, P = 0.63). (c) Representative fluorescence traces of L5 PYR somata expressing GCaMP6s in SNI or sham mice 1 week after surgery. (d) Average total integrated Ca2+ activity over 2.5 min in L5 PYR somata 1 week after surgery (SNI: 73.9 ± 5.5 ΔF, n = 51 cells from 4 mice; sham: 26.3 ± 1.6 ΔF, n = 30 cells from 2 mice; t79 = 6.535, P < 0.001). IP injection of MK801 reduced the activity of L5 PYR neurons (18.1 ± 1.0 ΔF, n = 12 cells; t61 = 4.895, P < 0.001). (e) Representative fluorescence traces of L5 PYR somata expressing GCaMP6s in SNI or sham mice 2 months after surgery. (f) Average total integrated Ca2+ activity over 2.5 min in L5 PYR somata 2 months after surgery (SNI: 54.8 ± 4.9 ΔF, n = 86 cells from 4 mice; sham: 20.4 ± 1.0 ΔF, n = 99 cells from 4 mice; t183 = 7.109, P < 0.001). Data are presented as means ± s.e.m. ***P < 0.001, two-way ANOVA followed by Bonferroni’s test (b), unpaired t test (d,f). (a,c,e) Representative images and traces from experiments carried out on at least 2 animals per group.

Supplementary Figure 2 Persistent elevation of L2/3 somatic Ca2+ activity in S1 after peripheral nerve injury.

(a–c) Representative fluorescence traces of L2/3 pyramidal (PYR) somata expressing GCaMP6s in SNI or sham at 1 week (a), 1 month (b), or 2 months (c) after surgery. (d) Average total integrated Ca2+ activity over 2.5 min in L2/3 PYR somata in SNI (1 week: 40.7 ± 1.9 ΔF, n = 138 cells from 4 mice; 1 month: 45.3 ± 3.1 ΔF, n = 36 cells from 5 mice; 2 months: 33.0 ± 2.7 ΔF, n = 89 cells from 4 mice) and sham mice (1 week: 27.7 ± 1.9 ΔF, n = 66 cells from 2 mice; 1 month: 28.8 ± 2.8 ΔF, n = 45 cells from 5 mice; 2 months: 17.1 ± 2.0 ΔF, n = 90 cells from 4 mice). SNI induced elevated Ca2+ activity at 1 week (t373 = 5.377, P < 0.001), 1 month (t79 = 2.991, P = 0.004), and 2 months (t177 = 4.973, P < 0.001) as compared to sham. Local application of MK801 to layer 1 significantly reduced L2/3 somatic Ca2+ activity in SNI (n = 134 cells from 4 mice; t373 = 10.48, P < 0.0001) and sham mice (n = 39 cells from 2 mice; t373 = 4.11, P < 0.001). L2/3 PYR neuron activity from ipsilateral S1 in SNI mice showed significant difference (n = 72 cells from 4 mice; t106 = 3.542, P < 0.001) from contralateral S1 at 1 month after surgery. Data are presented as means ± s.e.m. **P < 0.01, ***P < 0.001, two-way ANOVA followed by Bonferroni’s test for 1 week, unpaired t test for 1 month and 2 month. (a,b,c) Representative traces from experiments carried out on at least 2 animals per group.

Supplementary Figure 3 L5 apical tuft dendritic branch activity increases 1 week after peripheral nerve injury and persists for 2 months.

(a) Distribution of total integrated Ca2+ activity detected in apical tuft dendrites of SNI (n = 76 dendrites from 4 mice) and sham (n = 34 dendrites from 2 mice) mice 1 week after surgery (t108 = 5.527, P < 0.001). (b) Distribution of total integrated Ca2+ activity detected in apical tuft dendrites of SNI (n = 41 dendrites from 4 mice) and sham (n = 38 dendrites from 4 mice) mice 2 months after surgery (t77 = 3.729, P < 0.001). Data are presented as means ± s.e.m. ***P < 0.001, unpaired t test.

Supplementary Figure 4 SOM-expressing neuron activity 1 week and 1 month after peripheral nerve injury.

(a) Representative two-photon images of SOM-positive neurons expressing GCaMP6s in SNI mice 1 month after surgery. Yellow arrowheads point to active SOM axons in L1 (upper panel) and somata in L2/3 (lower panel). (b) Distribution of total integrated Ca2+ activity of SOM axonal boutons in L1 detected with GCaMP6s in SNI and sham mice 1 month after surgery (t139 = 9.008, P < 0.001). (c) Distribution of total integrated Ca2+ activity of L2/3 SOM somata detected with GCaMP6s in SNI (43.7 ± 3.8 F, n = 90 cells from 4 mice) and sham (95.3 ± 15.7 ΔF, n = 81 cells from 3 mice) mice 1 week after surgery (t169 = 3.267, P = 0.0013). (d) Distribution of total integrated Ca2+ activity of SOM somata detected with GCaMP6s in SNI and sham mice 1 month after surgery (t183 = 6.825, P < 0.001). **P < 0.01, ***P < 0.001, unpaired t test.

Supplementary Figure 5 PV- and VIP-expressing neuron activity 1 week after peripheral nerve injury.

(a) Representative two-photon images of PV-positive interneurons expressing GCaMP6s 1 week after surgery. Arrowheads point to somata. Scale bar, 20 μm. Recording imaging fields yielded 3 to 10 PV cells per field. (b) Distribution of total integrated Ca2+ activity of PV somata in SNI and sham mice 1 week after surgery (SNI: 22.2 ± 1.3 ΔF, n = 149 cells from 4 mice; sham: 62.3 ± 3.6 ΔF, n = 130 cells from 3 mice; t277 = 11.14, P < 0.001). (c) Representative two-photon images of VIP-positive interneurons expressing GCaMP6s. Arrowheads point to somata. Scale bar, 20 μm. Typically, there were 3 to 6 VIP cells within an imaging field. (d) Distribution of total integrated Ca2+ activity of VIP somata 1 week after surgery (SNI: 85.1 ± 5.0 ΔF, n = 133 cells from 3 mice; sham: 63.5 ± 4.2 ΔF, n = 106 cells from 2 mice; t237 = 3.209, P = 0.001). **P < 0.01, ***P < 0.001, unpaired t test. (e) Cartoon depicting cortical interneuron circuit in S1 following SNI (magenta dashed box) and sham (green dashed box) operations. SNI induces shifts in local interneuron network activity (↑VIP, ↓SOM, ↓PV) that contribute to increased L2/3 and L5 PYR neuronal activity. (a,c) Representative two-photon images from experiments carried out on at least 2 animals per group.

Supplementary Figure 6 Labeling density of SOM cells expressing GCaMP6 and hM3Dq-mcherry in S1.

(a) Representative confocal images of S1 following infection of Cre-dependent GCaMP6s in SOM-Cre mice. Scale bar, 100 μm. (b) The average number of GCaMP6-positive SOM cells in various cortical regions was quantified from 1 mm2 sections (slice thickness: 200 μm). There was no significant difference in the labeling of SOM cells with GCaMP6s between SNI and sham mice (t25 = 0.9813, P = 0.33, unpaired t test). (c) Representative confocal images of S1 following infection of Cre-dependent hM3Dq-mcherry in SOM-Cre mice. (d) Number of SOM cells expressing hM3Dq-mcherry in various cortical regions. The expression of hM3Dq was observed in S1, not in other cortical regions, such as frontal cortex, M1 and V1. There was no significant difference in the labeling of SOM cells with hM3Dq-mcherry between SNI and sham mice (t15 = 0.2372, P = 0.81, unpaired t test). Data are presented as means ± s.e.m.

Supplementary Figure 7 Acute activation of SOM neurons in S1 reduces L2/3 pyramidal neuron activity.

Percentage change in average total integrated Ca2+ activity of L2/3 pyramidal (PYR) neuron somata over 2.5 min following CNO application in SOM-Cre mice infected with hM3Dq-mcherry. PYR Ca2+ activity significantly decreased from baseline activity upon intraperitoneal CNO injection in SNI (-23.0 ± 5.4%, n = 42 cells from 2 mice, t41 = 4.226, P < 0.001, paired t test) and sham mice (-19.8 ± 4.9%, n = 46 cells from 3 mice, t45 = 4.032, P < 0.001). Data are presented as means ± s.e.m. ***P < 0.001.

Supplementary Figure 8 Expression of AAV-TurboRFP in cortex and effects of CNO on L5 pyramidal neuron activity and pain behavior.

(a) A control AAV vector (AAV-CMV-TurboRFP) was locally injected into S1 of SOM-Cre mice. The expression of TurboRFP in different cortical layers (L1 to L6) and regions (frontal, M1, S1, V1) was analyzed 2 weeks after injection. In both sham and SNI mice, the viral expression was mainly observed in L2/3 and L5 of S1. Scale bar, 100 μm. (b) Average signal intensity of TurboRFP signal across cortical sections (measured in AU). No significant difference was found between SNI and sham mice (P = 0.28, unpaired t test). (c) Dimensions of TurboRFP signal in cortical section, described in terms of depth (from pial surface) and width (horizontal spread) (measured in μm). No significant difference was found between SNI and sham infected mice (P = 0.99, two-way ANOVA followed by Bonferroni’s test). (d, e) In both sham and SNI, SOM-Cre mice infected with control vector AAV-CMV-TurboRFP, CNO injection had no effect on the activity of L5 PYR neurons (sham: P = 0.52, paired t test; SNI: P = 0.24, paired t test) (d) and the animals’ paw withdraw threshold in von Frey tests (sham: P = 0.51, paired t test; SNI: P = 0.96, paired t test) (e). Data are presented as means ± s.e.m.

Supplementary Figure 9 Labeling density of PV cells expressing hM3Dq-mcherry in S1.

(a) Representative confocal images of S1 following expression of hM3Dq-mCherry in PV-Cre mice. Scale bar, 100 μm. (b) Number of PV cells expressing hM3Dq-mCherry in various cortical regions. The expression of hM3Dq was mainly observed in S1, but not in other cortical regions such as frontal cortex, M1 and V1. There was no significant difference in the labeling of PV/hM3Dq-mcherry between SNI and sham mice (t11 = 1.459, P = 0.17, unpaired t test). Data are presented as means ± s.e.m.

Supplementary Figure 10 Peripheral nerve injury modulates the activity of interneuron networks to promote hyperactivity of pyramidal neurons in S1.

(a) A model showing the local circuitry of S1 in SNI (magenta dashed box) and sham (green dashed box) mice. VIP cells inhibit SOM and PV cells. PV cells inhibit the perisomatic region of L2/3 PYR neurons. SOM cells inhibit both PV and VIP cells as well as apical tuft dendrites of L2/3 and L5 PYR neurons. Following SNI, there is a reduction of SOM and PV cell activity and an increase in VIP cell activity (Fig. 4). This reduction of SOM-mediated inhibition on dendrites plus enhanced synaptic inputs associated with the pain state facilitate dendritic Ca2+ generation in apical tuft dendrites of L5 PYR neurons and promote a hyperactive state in S1 (Figs. 1, 2, 3). Additionally, increased VIP cell activity would further drive hyperactivity of PYR neurons through inhibition of SOM and PV cells. (b) Activation of SOM cells in L2/3 and L5 with DREADD variant hM3Dq (illustrated by orange syringe with CNO) restores SOM-mediated inhibition to the PYR dendrities and reduces PYR neuron activity in the neuropathic pain state (Figs. 5, 6).

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cichon, J., Blanck, T., Gan, WB. et al. Activation of cortical somatostatin interneurons prevents the development of neuropathic pain. Nat Neurosci 20, 1122–1132 (2017). https://doi.org/10.1038/nn.4595

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nn.4595

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing