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Natural and targeted circuit reorganization after spinal cord injury

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Abstract

A spinal cord injury disrupts communication between the brain and the circuits in the spinal cord that regulate neurological functions. The consequences are permanent paralysis, loss of sensation and debilitating dysautonomia. However, the majority of circuits located above and below the injury remain anatomically intact, and these circuits can reorganize naturally to improve function. In addition, various neuromodulation therapies have tapped into these processes to further augment recovery. Emerging research is illuminating the requirements to reconstitute damaged circuits. Here, we summarize these natural and targeted reorganizations of circuits after a spinal cord injury. We also advocate for new concepts of reorganizing circuits informed by multi-omic single-cell atlases of recovery from injury. These atlases will uncover the molecular logic that governs the selection of 'recovery-organizing' neuronal subpopulations, and are poised to herald a new era in spinal cord medicine.

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Fig. 1: Adaptive and maladaptive reorganization of brain, brainstem and spinal circuits following spinal cord injury.
Fig. 2: Neuromodulation of anatomically intact circuits.
Fig. 3: Mechanisms through which epidural electrical stimulation restores hemodynamics and mobility.
Fig. 4: Biological strategies to reconstitute damaged circuits.

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Change history

  • 02 March 2023

    In the version of this article initially published, the green and orange elements in the top-right inset box of Figure 1 were missing and have now been restored in the HTML and PDF version of the article.

References

  1. Skinnider, M. A. et al. Cell type prioritization in single-cell data. Nat. Biotechnol. 39, 30–34 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  2. Osseward, P. J. et al. Conserved genetic signatures parcellate cardinal spinal neuron classes into local and projection subsets. Science 372, 385–393 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Arber, S. & Costa, R. M. Connecting neuronal circuits for movement. Science 360, 1403–1404 (2018).

    Article  CAS  PubMed  Google Scholar 

  4. Pivetta, C., Esposito, M. S., Sigrist, M. & Arber, S. Motor-circuit communication matrix from spinal cord to brainstem neurons revealed by developmental origin. Cell 156, 537–548 (2014).

    Article  CAS  PubMed  Google Scholar 

  5. Asboth, L. et al. Cortico-reticulo-spinal circuit reorganization enables functional recovery after severe spinal cord contusion. Nat. Neurosci. 21, 576–588 (2018).

    Article  CAS  PubMed  Google Scholar 

  6. Sofroniew, M. V. Dissecting spinal cord regeneration. Nature 557, 343–350 (2018).

    Article  CAS  PubMed  Google Scholar 

  7. Kathe, C., Hutson, T. H., McMahon, S. B. & Moon, L. D. F. Intramuscular neurotrophin-3 normalizes low threshold spinal reflexes, reduces spasms and improves mobility after bilateral corticospinal tract injury in rats. Elife 5, e18146 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  8. Taweel, W. A. & Seyam, R. Neurogenic bladder in spinal cord injury patients. Res. Rep. Urol. 7, 85–99 (2015).

    PubMed  PubMed Central  Google Scholar 

  9. Courtine, G. et al. Performance of locomotion and foot grasping following a unilateral thoracic corticospinal tract lesion in monkeys (Macaca mulatta). Brain 128, 2338–2358 (2005).

    Article  PubMed  Google Scholar 

  10. Freund, P. et al. MRI investigation of the sensorimotor cortex and the corticospinal tract after acute spinal cord injury: a prospective longitudinal study. Lancet Neurol. 12, 873–881 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Nishimura, Y. et al. Time-dependent central compensatory mechanisms of finger dexterity after spinal cord injury. Science 318, 1150–1155 (2007).

    Article  CAS  PubMed  Google Scholar 

  12. Hollis, E. R. 2nd et al. Ryk controls remapping of motor cortex during functional recovery after spinal cord injury. Nat. Neurosci. 19, 697–705 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Bareyre, F. M. et al. The injured spinal cord spontaneously forms a new intraspinal circuit in adult rats. Nat. Neurosci. 7, 269–277 (2004).

    Article  CAS  PubMed  Google Scholar 

  14. Hilton, B. J. et al. Reestablishment of cortical motor output maps and spontaneous functional recovery via spared dorsolaterally projecting corticospinal neurons after dorsal column spinal cord injury in adult mice. J. Neurosci. 36, 4080–4092 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  15. Ghosh, A. et al. Rewiring of hindlimb corticospinal neurons after spinal cord injury. Nat. Neurosci. 13, 97–104 (2010).

    Article  CAS  PubMed  Google Scholar 

  16. Kaas, J. H. et al. Cortical and subcortical plasticity in the brains of humans, primates, and rats after damage to sensory afferents in the dorsal columns of the spinal cord. Exp. Neurol. 209, 407–416 (2008).

    Article  PubMed  Google Scholar 

  17. Rosenzweig, E. S. et al. Extensive spontaneous plasticity of corticospinal projections after primate spinal cord injury. Nat. Neurosci. 13, 1505–1510 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Brand, Rvanden et al. Restoring voluntary control of locomotion after paralyzing spinal cord injury. Science 336, 1182–1185 (2012).

    Article  PubMed  Google Scholar 

  19. Rosenzweig, E. S. et al. Extensive spontaneous plasticity of corticospinal projections after primate spinal cord injury. Nat. Neurosci. 13, 1505–1510 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Rosenzweig, E. S. et al. Chondroitinase improves anatomical and functional outcomes after primate spinal cord injury. Nat. Neurosci. 22, 1269–1275 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Poplawski, G. H. D. et al. Injured adult neurons regress to an embryonic transcriptional growth state. Nature 581, 77–82 (2020).

    Article  CAS  PubMed  Google Scholar 

  22. Friedli, L. et al. Pronounced species divergence in corticospinal tract reorganization and functional recovery after lateralized spinal cord injury favors primates. Sci. Transl. Med. 7, 302ra134 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  23. Siegel, C. S., Fink, K. L., Strittmatter, S. M. & Cafferty, W. B. J. Plasticity of intact rubral projections mediates spontaneous recovery of function after corticospinal tract injury. J. Neurosci. 35, 1443–1457 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Mosberger, A. C. et al. Axotomized corticospinal neurons increase supra-lesional innervation and remain crucial for skilled reaching after bilateral pyramidotomy. Cereb. Cortex 28, 625–643 (2017).

    Google Scholar 

  25. Zaaimi, B., Edgley, S. A., Soteropoulos, D. S. & Baker, S. N. Changes in descending motor pathway connectivity after corticospinal tract lesion in macaque monkey. Brain 135, 2277–2289 (2012).

    Article  PubMed  PubMed Central  Google Scholar 

  26. Filli, L. et al. Bridging the gap: a reticulo-propriospinal detour bypassing an incomplete spinal cord injury. J. Neurosci. 34, 13399–13410 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Kwon, B. K. et al. Survival and regeneration of rubrospinal neurons 1 year after spinal cord injury. Proc. Natl Acad. Sci. USA 99, 3246–3251 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Alilain, W. J., Horn, K. P., Hu, H., Dick, T. E. & Silver, J. Functional regeneration of respiratory pathways after spinal cord injury. Nature 475, 196–200 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Müllner, A. et al. Lamina‐specific restoration of serotonergic projections after Nogo‐A antibody treatment of spinal cord injury in rats. Eur. J. Neurosci. 27, 326–333 (2008).

    Article  PubMed  Google Scholar 

  30. Sawada, M. et al. Function of the nucleus accumbens in motor control during recovery after spinal cord injury. Science 350, 98–101 (2015).

    Article  CAS  PubMed  Google Scholar 

  31. Shik, M. L., Severin, F. V. & Orlovskiĭ, G. N. Control of walking and running by means of electric stimulation of the midbrain. Biofizika 11, 659–666 (1966).

    CAS  PubMed  Google Scholar 

  32. Ryczko, D. & Dubuc, R. The multifunctional mesencephalic locomotor region. Curr. Pharm. Des. 19, 4448–4470 (2013).

    Article  CAS  PubMed  Google Scholar 

  33. Bonizzato, M. et al. Multi-pronged neuromodulation intervention engages the residual motor circuitry to facilitate walking in a rat model of spinal cord injury. Nat. Commun. 12, 1925 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  34. Caggiano, V. et al. Midbrain circuits that set locomotor speed and gait selection. Nature 553, 455–460 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Esposito, M. S., Capelli, P. & Arber, S. Brainstem nucleus MdV mediates skilled forelimb motor tasks. Nature 508, 351–356 (2014).

    Article  CAS  PubMed  Google Scholar 

  36. Ferreira-Pinto, M. J. et al. Functional diversity for body actions in the mesencephalic locomotor region. Cell 184, 4564–4578 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Ruder, L. et al. A functional map for diverse forelimb actions within brainstem circuitry. Nature 590, 445–450 (2021).

    Article  CAS  PubMed  Google Scholar 

  38. Kinoshita, M. et al. Genetic dissection of the circuit for hand dexterity in primates. Nature 487, 235–238 (2012).

    Article  CAS  PubMed  Google Scholar 

  39. Chen, B. et al. Reactivation of dormant relay pathways in injured spinal cord by KCC2 manipulations. Cell 174, 521–535 (2018).

    Article  Google Scholar 

  40. Courtine, G. et al. Recovery of supraspinal control of stepping via indirect propriospinal relay connections after spinal cord injury. Nat. Med. 14, 69–74 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. García-Alías, G., Barkhuysen, S., Buckle, M. & Fawcett, J. W. Chondroitinase ABC treatment opens a window of opportunity for task-specific rehabilitation. Nat. Neurosci. 12, 1145–1151 (2009).

    Article  PubMed  Google Scholar 

  42. Courtine, G. & Sofroniew, M. V. Spinal cord repair: advances in biology and technology. Nat. Med. 25, 898–908 (2019).

    Article  CAS  PubMed  Google Scholar 

  43. Lanuza, G. M., Gosgnach, S., Pierani, A., Jessell, T. M. & Goulding, M. Genetic identification of spinal interneurons that coordinate left–right locomotor activity necessary for walking movements. Neuron 42, 375–386 (2004).

    Article  CAS  PubMed  Google Scholar 

  44. Gosgnach, S. et al. V1 spinal neurons regulate the speed of vertebrate locomotor outputs. Nature 440, 215–219 (2006).

    Article  CAS  PubMed  Google Scholar 

  45. Courtine, G. et al. Transformation of nonfunctional spinal circuits into functional states after the loss of brain input. Nat. Neurosci. 12, 1333–1342 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Caudle, K. L. et al. Hindlimb immobilization in a wheelchair alters functional recovery following contusive spinal cord injury in the adult rat. Neurorehabil. Neural Repair 25, 729–739 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  47. Côté, M.-P., Azzam, G. A., Lemay, M. A., Zhukareva, V. & Houlé, J. D. Activity-dependent increase in neurotrophic factors is associated with an enhanced modulation of spinal reflexes after spinal cord injury. J. Neurotrauma 28, 299–309 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  48. Ichiyama, R. M. et al. Step training reinforces specific spinal locomotor circuitry in adult spinal rats. J. Neurosci. 28, 7370–7375 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Takeoka, A., Vollenweider, I., Courtine, G. & Arber, S. Muscle spindle feedback directs locomotor recovery and circuit reorganization after spinal cord injury. Cell 159, 1626–1639 (2014).

    Article  CAS  PubMed  Google Scholar 

  50. Hutson, T. H. et al. Cbp-dependent histone acetylation mediates axon regeneration induced by environmental enrichment in rodent spinal cord injury models. Sci. Transl. Med. 11, eaaw2064 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Satkunendrarajah, K., Karadimas, S. K., Laliberte, A. M., Montandon, G. & Fehlings, M. G. Cervical excitatory neurons sustain breathing after spinal cord injury. Nature 562, 419–422 (2018).

    Article  CAS  PubMed  Google Scholar 

  52. Kathe, C. et al. The neurons that restore walking after paralysis. Nature https://doi.org/10.1038/s41586-022-05385-7 (2022).

  53. Zholudeva, L. V., Karliner, J. S., Dougherty, K. J. & Lane, M. A. Anatomical recruitment of spinal V2a interneurons into phrenic motor circuitry after high cervical spinal cord injury. J. Neurotrauma 34, 3058–3065 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  54. Bui, T. V., Stifani, N., Akay, T. & Brownstone, R. M. Spinal microcircuits comprising dI3 interneurons are necessary for motor functional recovery following spinal cord transection. Elife 5, e21715 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  55. Sathyamurthy, A. et al. Massively parallel single nucleus transcriptional profiling defines spinal cord neurons and their activity during behavior. Cell Rep. 22, 2216–2225 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Russ, D. E. et al. A harmonized atlas of mouse spinal cord cell types and their spatial organization. Nat. Commun. 12, 5722 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Overman, J. J. & Carmichael, S. T. Plasticity in the injured brain. Neuroscientist 20, 15–28 (2014).

    Article  PubMed  Google Scholar 

  58. Pozo, K. & Goda, Y. Unraveling mechanisms of homeostatic synaptic plasticity. Neuron 66, 337–351 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Squair, J. W., West, C. R. & Krassioukov, A. V. Neuroprotection, plasticity manipulation, and regenerative strategies to improve cardiovascular function following spinal cord injury. J. Neurotrauma 32, 609–621 (2015).

    Article  PubMed  Google Scholar 

  60. Krassioukov, A. V., Johns, D. G. & Schramm, L. P. Sensitivity of sympathetically correlated spinal interneurons, renal sympathetic nerve activity, and arterial pressure to somatic and visceral stimuli after chronic spinal injury. J. Neurotrauma 19, 1521–1529 (2002).

    Article  PubMed  Google Scholar 

  61. Brennan, F. H. et al. Acute post-injury blockade of α2̣δ-1 calcium channel subunits prevents pathological autonomic plasticity after spinal cord injury. Cell Rep. 34, 108667 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Li, Y. et al. Pericytes impair capillary blood flow and motor function after chronic spinal cord injury. Nat. Med. 23, 733–741 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. D’Amico, J. M. et al. Constitutively active 5-HT2/α1 receptors facilitate muscle spasms after human spinal cord injury. J. Neurophysiol. 109, 1473–1484 (2013).

    Article  PubMed  Google Scholar 

  64. Husch, A. et al. Spinal cord injury induces serotonin supersensitivity without increasing intrinsic excitability of mouse V2a Interneurons. J. Neurosci. 32, 13145–13154 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Boulenguez, P. et al. Down-regulation of the potassium-chloride cotransporter KCC2 contributes to spasticity after spinal cord injury. Nat. Med. 16, 302–307 (2010).

    Article  CAS  PubMed  Google Scholar 

  66. Bellardita, C. et al. Spatiotemporal correlation of spinal network dynamics underlying spasms in chronic spinalized mice. Elife 6, e23011 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  67. Marcantoni, M. et al. Early delivery and prolonged treatment with nimodipine prevents the development of spasticity after spinal cord injury in mice. Sci. Transl. Med. 12, eaay0167 (2020).

    Article  CAS  PubMed  Google Scholar 

  68. Beauparlant, J. et al. Undirected compensatory plasticity contributes to neuronal dysfunction after severe spinal cord injury. Brain 136, 3347–3361 (2013).

    Article  PubMed  Google Scholar 

  69. Elbasiouny, S. M., Moroz, D., Bakr, M. M. & Mushahwar, V. K. Management of spasticity after spinal cord injury: current techniques and future directions. Neurorehabil. Neural Repair 24, 23–33 (2010).

    Article  PubMed  Google Scholar 

  70. Groat, W. C de & Yoshimura, N. Mechanisms underlying the recovery of lower urinary tract function following spinal cord injury. Prog. Brain Res. 152, 59–84 (2006).

    Article  PubMed  Google Scholar 

  71. Kramer, J. L. K. et al. Neuropathic pain following traumatic spinal cord injury: models, measurement and mechanisms. J. Neurosci. Res. 95, 1295–1306 (2017).

    Article  CAS  PubMed  Google Scholar 

  72. Hou, S. & Rabchevsky, A. G. Autonomic consequences of spinal cord injury. Compr. Physiol. 4, 1419–1453 (2017).

    Google Scholar 

  73. Zholudeva, L. V. et al. Spinal Interneurons as gatekeepers to neuroplasticity after injury or disease. J. Neurosci. 41, 845–854 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Manno, G. L. et al. Molecular architecture of the developing mouse brain. Nature 596, 92–96 (2021).

    Article  PubMed  Google Scholar 

  75. Squair, J. W. et al. Confronting false discoveries in single-cell differential expression. Nat. Commun. 12, 5692 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Cao, J. et al. The single-cell transcriptional landscape of mammalian organogenesis. Nature 566, 496–502 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  77. Zappia, L. & Theis, F. J. Over 1,000 tools reveal trends in the single-cell RNA-seq analysis landscape. Genome Biol. 22, 301 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  78. Bonizzato, M. & Martinez, M. An intracortical neuroprosthesis immediately alleviates walking deficits and improves recovery of leg control after spinal cord injury. Sci. Transl. Med. 13, eabb4422 (2021).

    Article  PubMed  Google Scholar 

  79. Carmel, J. B., Kimura, H. & Martin, J. H. Electrical stimulation of motor cortex in the uninjured hemisphere after chronic unilateral injury promotes recovery of skilled locomotion through ipsilateral control. J. Neurosci. 34, 462–466 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Nishimura, Y., Perlmutter, S. I., Eaton, R. W. & Fetz, E. E. Spike-timing-dependent plasticity in primate corticospinal connections induced during free behavior. Neuron 80, 1301–1309 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. McPherson, J. G., Miller, R. R. & Perlmutter, S. I. Targeted, activity-dependent spinal stimulation produces long-lasting motor recovery in chronic cervical spinal cord injury. Proc. Natl Acad. Sci. USA 112, 12193–12198 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  82. Christiansen, L. & Perez, M. A. Targeted-plasticity in the corticospinal tract after human spinal cord injury. Neurotherapeutics 15, 618–627 (2018).

    Article  Google Scholar 

  83. Darrow, M. J. et al. Vagus nerve stimulation paired with rehabilitative training enhances motor recovery after bilateral spinal cord injury to cervical forelimb motor pools. Neurorehabil. Neural Repair 34, 200–209 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  84. Ganzer, P. D. et al. Closed-loop neuromodulation restores network connectivity and motor control after spinal cord injury. Elife 7, e32058 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  85. Thevathasan, W. et al. Pedunculopontine nucleus deep brain stimulation in Parkinson’s disease: a clinical review. Mov. Disord. 33, 10–20 (2018).

    Article  PubMed  Google Scholar 

  86. Sherrington, C. S. The Integrative Action of The Nervous System https://doi.org/10.1037/13798-000 (Yale Univ. Press, 1906).

  87. Dimitrijevic, M. R., Gerasimenko, Y. & Pinter, M. M. Evidence for a spinal central pattern generator in humans. Ann. NY Acad. Sci. 860, 360–376 (1998).

    Article  CAS  PubMed  Google Scholar 

  88. Angeli, C. A. et al. Recovery of over-ground walking after chronic motor complete spinal cord injury. N. Engl. J. Med. 379, 1244–1250 (2018).

    Article  PubMed  Google Scholar 

  89. Wagner, F. B. et al. Targeted neurotechnology restores walking in humans with spinal cord injury. Nature 563, 65–71 (2018).

    Article  CAS  PubMed  Google Scholar 

  90. Holinski, B. J., Mazurek, K. A., Everaert, D. G., Stein, R. B. & Mushahwar, V. K. Restoring stepping after spinal cord injury using intraspinal microstimulation and novel control strategies. Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. 2011, 5798–5801 (2011).

    PubMed  Google Scholar 

  91. Gerasimenko, Y. et al. Transcutaneous electrical spinal-cord stimulation in humans. Ann. Phys. Rehabil. Med. 58, 225–231 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  92. Harkema, S. et al. Effect of epidural stimulation of the lumbosacral spinal cord on voluntary movement, standing, and assisted stepping after motor complete paraplegia: a case study. Lancet 377, 1938–1947 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  93. Barbeau, H. & Rossignol, S. Recovery of locomotion after chronic spinalization in the adult cat. Brain Res. 412, 84–95 (1987).

    Article  CAS  PubMed  Google Scholar 

  94. Capogrosso, M. et al. A computational model for epidural electrical stimulation of spinal sensorimotor circuits. J. Neurosci. 33, 19326–19340 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  95. Formento, E. et al. Electrical spinal cord stimulation must preserve proprioception to enable locomotion in humans with spinal cord injury. Nat. Neurosci. 21, 1728–1741 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  96. Meyer, C. et al. Immediate effects of transcutaneous spinal cord stimulation on motor function in chronic, sensorimotor incomplete spinal cord injury. J. Clin. Med. 9, 3541 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  97. Moraud, E. M. et al. Mechanisms underlying the neuromodulation of spinal circuits for correcting gait and balance deficits after spinal cord injury. Neuron 89, 814–828 (2016).

    Article  Google Scholar 

  98. Wenger, N. et al. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury. Nat. Med. 22, 138–145 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  99. Capogrosso, M. et al. A brain–spine interface alleviating gait deficits after spinal cord injury in primates. Nature 539, 284–288 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  100. Minev, I. R. et al. Electronic dura mater for long-term multimodal neural interfaces. Science 347, 159–163 (2015).

    Article  CAS  PubMed  Google Scholar 

  101. Capogrosso, M. et al. Configuration of electrical spinal cord stimulation through real-time processing of gait kinematics. Nat. Protoc. 13, 2031–2061 (2018).

    Article  CAS  PubMed  Google Scholar 

  102. Cappellini, G., Ivanenko, Y. P., Dominici, N., Poppele, R. E. & Lacquaniti, F. Migration of motor pool activity in the spinal cord reflects body mechanics in human locomotion. J. Neurophysiol. 104, 3064–3073 (2010).

    Article  PubMed  Google Scholar 

  103. Rowald, A. et al. Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis. Nat. Med. https://doi.org/10.1038/s41591-021-01663-5 (2022).

  104. Barra, B. et al. Epidural electrical stimulation of the cervical dorsal roots restores voluntary upper limb control in paralyzed monkeys. Nat. Neurosci. 25, 924–934 (2022).

    Article  CAS  PubMed  Google Scholar 

  105. Lu, D. C. et al. Engaging cervical spinal cord networks to reenable volitional control of hand function in tetraplegic patients. Neurorehabil. Neural Repair 30, 951–962 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  106. Fouad, K., Popovich, P. G., Kopp, M. A. & Schwab, J. M. The neuroanatomical–functional paradox in spinal cord injury. Nat. Rev. Neurol. 17, 53–62 (2021).

    Article  PubMed  Google Scholar 

  107. Schnell, L. & Schwab, M. E. Axonal regeneration in the rat spinal cord produced by an antibody against myelin-associated neurite growth inhibitors. Nature 343, 269–272 (1990).

    Article  CAS  PubMed  Google Scholar 

  108. Lee, J. K. et al. Assessing spinal axon regeneration and sprouting in Nogo-, MAG- and OMgp-deficient mice. Neuron 66, 663–670 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  109. Squair, J. W., Gautier, M., Sofroniew, M. V., Courtine, G. & Anderson, M. A. Engineering spinal cord repair. Curr. Opin. Biotech. 72, 48–53 (2021).

    Article  CAS  PubMed  Google Scholar 

  110. Hellal, F. et al. Microtubule stabilization reduces scarring and causes axon regeneration after spinal cord injury. Science 331, 928–931 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  111. Park, K. K. et al. Promoting axon regeneration in the adult CNS by modulation of the PTEN/mTOR pathway. Science 322, 963–966 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  112. Sun, F. et al. Sustained axon regeneration induced by co-deletion of PTEN and SOCS3. Nature 480, 372–375 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  113. Wang, Z., Reynolds, A., Kirry, A., Nienhaus, C. & Blackmore, M. G. Overexpression of Sox11 promotes corticospinal tract regeneration after spinal injury while interfering with functional recovery. J. Neurosci. 35, 3139–3145 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  114. Liu, Y. et al. A sensitized IGF1 treatment restores corticospinal axon-dependent functions. Neuron 95, 817–833 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  115. Anderson, M. A. et al. Required growth facilitators propel axon regeneration across complete spinal cord injury. Nature 561, 396–400 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  116. Wang, Z. et al. KLF6 and STAT3 co-occupy regulatory DNA and functionally synergize to promote axon growth in CNS neurons. Sci. Rep. 8, 12565 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  117. Stern, S. et al. RhoA drives actin compaction to restrict axon regeneration and astrocyte reactivity after CNS injury. Neuron 109, 3436–3455 (2021).

    Article  CAS  PubMed  Google Scholar 

  118. Anderson, M. A. Targeting central nervous system regeneration with cell type specificity. Neurosurg. Clin. N. Am. 32, 397–405 (2021).

    Article  PubMed  Google Scholar 

  119. Lovett-Barr, M. R. et al. Repetitive intermittent hypoxia induces respiratory and somatic motor recovery after chronic cervical spinal injury. J. Neurosci. 32, 3591–3600 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  120. Duan, X. et al. Subtype-specific regeneration of retinal ganglion cells following axotomy: effects of osteopontin and mTOR signaling. Neuron 85, 1244–1256 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  121. Anderson, M. A. et al. Astrocyte scar formation aids central nervous system axon regeneration. Nature 532, 195–200 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  122. Ramón y Cajal, S., DeFelipe, J. & Jones, E. G. Cajal’s Degeneration and Regeneration of the Nervous System (Oxford Univ. Press, Oxford, 1991).

  123. Alto, L. T. et al. Chemotropic guidance facilitates axonal regeneration and synapse formation after spinal cord injury. Nat. Neurosci. 12, 1106–1113 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  124. Lu, P. et al. Motor axonal regeneration after partial and complete spinal cord transection. J. Neurosci. 32, 8208–8218 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  125. Assinck, P., Duncan, G. J., Hilton, B. J., Plemel, J. R. & Tetzlaff, W. Cell transplantation therapy for spinal cord injury. Nat. Neurosci. 20, 637–647 (2017).

    Article  CAS  PubMed  Google Scholar 

  126. Lu, P. et al. Long-distance growth and connectivity of neural stem cells after severe spinal cord injury. Cell 150, 1264–1273 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  127. Rosenzweig, E. S. et al. Restorative effects of human neural stem cell grafts on the primate spinal cord. Nat. Med. 24, 484–490 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  128. Abematsu, M. et al. Neurons derived from transplanted neural stem cells restore disrupted neuronal circuitry in a mouse model of spinal cord injury. J. Clin. Invest. 120, 3255–3266 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  129. Zholudeva, L. V. et al. Transplantation of neural progenitors and V2a interneurons after spinal cord injury. J. Neurotrauma 35, 2883–2903 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  130. Rocca, M. A. et al. Clinical and imaging assessment of cognitive dysfunction in multiple sclerosis. Lancet Neurol. 14, 302–317 (2015).

    Article  PubMed  Google Scholar 

  131. Chung, K. & Deisseroth, K. CLARITY for mapping the nervous system. Nat. Methods 10, 508–513 (2013).

    Article  CAS  PubMed  Google Scholar 

  132. Srivatsan, S. R. et al. Embryo-scale, single-cell spatial transcriptomics. Science 373, 111–117 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  133. Fenno, L. E. et al. Targeting cells with single vectors using multiple-feature Boolean logic. Nat. Methods 11, 763–772 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  134. Bruns, T. M., Weber, D. J. & Gaunt, R. A. Microstimulation of afferents in the sacral dorsal root ganglia can evoke reflex bladder activity. Neurourol. Urodyn. 34, 65–71 (2015).

    Article  PubMed  Google Scholar 

  135. West, C. R. et al. Association of epidural stimulation with cardiovascular function in an individual with spinal cord injury. JAMA Neurol. 75, 630–632 (2018).

    Article  PubMed  Google Scholar 

  136. Squair, J. W. et al. Neuroprosthetic baroreflex controls haemodynamics after spinal cord injury. Nature 590, 308–314 (2021).

    Article  CAS  PubMed  Google Scholar 

  137. Squair, J. W. et al. Implanted system for orthostatic hypotension in multiple-system atrophy. N. Engl. J. Med. 386, 1339–1344 (2022).

    Article  PubMed  Google Scholar 

  138. Göritz, C. et al. A pericyte origin of spinal cord scar tissue. Science 333, 238–242 (2011).

    Article  PubMed  Google Scholar 

  139. Soderblom, C. et al. Perivascular fibroblasts form the fibrotic scar after contusive spinal cord injury. J. Neurosci. 33, 13882–13887 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  140. Dorrier, C. E. et al. CNS fibroblasts form a fibrotic scar in response to immune cell infiltration. Nat. Neurosci. 24, 234–244 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  141. Dias, D. O. et al. Reducing pericyte-derived scarring promotes recovery after spinal cord injury. Cell 173, 153–165 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  142. Herrmann, J. E. et al. STAT3 is a critical regulator of astrogliosis and scar formation after spinal cord injury. J. Neurosci. 28, 7231–7243 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  143. Chen, M. et al. Leucine zipper-bearing kinase is a critical regulator of astrocyte reactivity in the adult mammalian CNS. Cell Rep. 22, 3587–3597 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  144. Wanner, I. B. et al. Glial scar borders are formed by newly proliferated, elongated astrocytes that interact to corral inflammatory and fibrotic cells via STAT3-dependent mechanisms after spinal cord injury. J. Neurosci. 33, 12870–12886 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  145. Anderson, M. A., Ao, Y. & Sofroniew, M. V. Heterogeneity of reactive astrocytes. Neurosci. Lett. 565, 23–29 (2014).

    Article  CAS  PubMed  Google Scholar 

  146. Faulkner, J. R. et al. Reactive astrocytes protect tissue and preserve function after spinal cord injury. J. Neurosci. 24, 2143–2155 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  147. Bartus, K. et al. Large-scale chondroitin sulfate proteoglycan digestion with chondroitinase gene therapy leads to reduced pathology and modulates macrophage phenotype following spinal cord contusion injury. J. Neurosci. 34, 4822–4836 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  148. Liu, K. et al. PTEN deletion enhances the regenerative ability of adult corticospinal neurons. Nat. Neurosci. 13, 1075–1081 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

We acknowledge support from Defitech Foundation, the Swiss National Science Foundation (Ambizione Fellowship PZ00P3_185728 to M.A.A.) and subsidy to G.C. (310030_192558), Swiss National Science Foundation (32003BE_205563), European Research Council (ERC-2015-CoG HOW2WALKAGAIN 682999; Marie Sklodowska-Curie individual fellowship 842578 to J.W.S.), H2020-MSCA-COFUND-2016 EPFL Fellows program (665667 to C.K.), the Morton Cure Paralysis Foundation (to M.A.A.), the ALARME Foundation (to M.A.A. and G.C.) and the Human Frontiers in Science Program long-term fellowship (LT001278/2017-L to C.K.).

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Correspondence to Grégoire Courtine.

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G.C., J.B. and J.W.S. hold various patents in relation with some of the present work. G.C. and J.B. are consultants of ONWARD medical. G.C. and J.B. are minority shareholders of ONWARD, a company with partial relationships with some of the presented work. The remaining authors declare no competing interests.

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Anderson, M.A., Squair, J.W., Gautier, M. et al. Natural and targeted circuit reorganization after spinal cord injury. Nat Neurosci 25, 1584–1596 (2022). https://doi.org/10.1038/s41593-022-01196-1

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