title: Lost in the jungle: new hurdles for optic nerve axon regeneration.
abstract: The poor regenerative capacity of injured central nervous system (CNS) axons leads to permanent neurological deficits after brain, spinal cord, or optic nerve lesions. In the optic nerve, recent studies showed that stimulation of the cytokine or mammalian target of rapamycin (mTOR) signaling pathways potently enhances sprouting and regeneration of injured retinal ganglion cell axons in adult mice, but does not allow the majority of axons to reach their main cerebral targets. New analyses have revealed axon navigation defects in the optic nerve and at the optic chiasm under conditions of strong growth stimulation. We propose that a balanced growth stimulatory treatment will have to be combined with guidance factors and suppression of local growth inhibitory factors to obtain the full regeneration of long CNS axonal tracts.
authors.affiliation: Brain Research Institute, University of Zürich, and Department of Health Sciences and Technology, ETH Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. Electronic address: pernet@hifo.uzh.ch.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pernet
authors.affiliation: Brain Research Institute, University of Zürich, and Department of Health Sciences and Technology, ETH Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. Electronic address: schwab@hifo.uzh.ch.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Schwab
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology*; D020221:Optic Nerve Injuries / Q000473:pathology* / Q000503:physiopathology*; D012160:Retina / Q000502:physiology; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D050796:STAT3 Transcription Factor; D058570:TOR Serine-Threonine Kinases
keywords: Stat3; axonal misguidance; axonal regeneration; mTOR; neurotrophic factors; optic nerve injury