Growth and guidance cues for regenerating axons: where have they gone?
Both attractive and repellent cues are required to guide developing axons to their targets in the central nervous system. Critical guidance molecules in the developing brain include the semaphorins, netrins, slits, and ephrins. Current research indicates that many of these molecules and their receptors are expressed in the adult central nervous system (CNS), and that injury can alter the levels of these ligands/receptors. Recent studies have begun the process of elucidating the functions of these receptors in adult mammals, and the effects that they have on the regeneration of adult neurons. This review addresses our current knowledge with respect to the response of adult CNS neurons to axonal injury, interventions for enhancing the survival and regeneration of injured neurons, and the expression of developmental axon guidance cues in the injured mature CNS, with specific focus on the retino-tectal projection.
Department of Neurology, Faculty of Medicine, University of Göttingen, Germany.
Paulo D
PD
Koeberle
Mathias
M
Bähr
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001369:Axons / Q000502:physiology*; D001930:Brain Injuries / Q000503:physiopathology / Q000628:therapy; D002490:Central Nervous System / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D003463:Cues; D036342:Ephrins / Q000378:metabolism; D007839:Functional Laterality / Q000502:physiology; D008959:Models, Neurological; D009185:Myelin Proteins / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism; D009416:Nerve Regeneration / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D000070798:Nogo Proteins; D010525:Peripheral Nerves / Q000637:transplantation; D012165:Retinal Ganglion Cells / Q000502:physiology; D039961:Semaphorins / Q000378:metabolism; D019737:Transplants
D036342:Ephrins; D009185:Myelin Proteins; D009414:Nerve Growth Factors; D000070798:Nogo Proteins; D039961:Semaphorins