Mammalian neurons lose the ability to regenerate their central nervous system axons as they mature during embryonic or early postnatal development. Neuronal maturation requires a transformation from a situation in which neuronal components grow and assemble to one in which these components are fixed and involved in the machinery for effective information transmission and computation. To regenerate after injury, neurons need to overcome this fixed state to reactivate their growth programme. A variety of intracellular processes involved in initiating or sustaining neuronal maturation, including the regulation of gene expression, cytoskeletal restructuring and shifts in intracellular trafficking, have been shown to prevent axon regeneration. Understanding these processes will contribute to the identification of targets to promote repair after injury or disease.

Centre for Reconstructive Neuroscience Institute for Experimental Medicine Czech Academy of Science Prague Czechia

Department of Cellular and Physiological Sciences Faculty of Medicine University of British Columbia Vancouver British Columbia Canada

Department of Clinical Neurosciences John van Geest Centre for Brain Repair University of Cambridge Cambridge UK

Djavad Mowafaghian Centre for Brain Health University of British Columbia Vancouver British Columbia Canada

International Collaboration on Repair Discoveries University of British Columbia Vancouver British Columbia Canada

Laboratory for Axonal Growth and Regeneration German Center for Neurodegenerative Diseases Bonn Germany

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Activated alpha 9 integrin expression enables sensory pathway reconstruction after spinal cord injury