title: Neurotrophin release by neurotrophins: implications for activity-dependent neuronal plasticity.
abstract: Neurotrophins, secreted in an activity-dependent manner, are thought to be involved in the activity-dependent refinement of synaptic connections. Here we demonstrate that in hippocampal neurons and the rat pheochromocytoma cell line PC12 application of exogenous neurotrophins induces secretion of neurotrophins, an effect that is mediated by the activation of tyrosine kinase neurotrophin receptors (Trks). Like activity-dependent secretion of neurotrophins, neurotrophin-induced neurotrophin secretion requires mobilization of calcium from intracellular stores. Because neurotrophins are likely to be released from both dendrites and axons, neurotrophin-induced neurotrophin release represents a potential positive feedback mechanism, contributing to the reinforcement and stabilization of synaptic connections.
authors.affiliation: Department of Neurobiochemistry, Max Planck Institute for Psychiatry, Martinsried, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Canossa
authors.forename: O
authors.initials: O
authors.lastname: Griesbeck
authors.forename: B
authors.initials: B
authors.lastname: Berninger
authors.forename: G
authors.initials: G
authors.lastname: Campana
authors.forename: R
authors.initials: R
authors.lastname: Kolbeck
authors.forename: H
authors.initials: H
authors.lastname: Thoenen
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D018698:Glutamic Acid / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D066298:In Vitro Techniques; D009414:Nerve Growth Factors / Q000378:metabolism / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D016716:PC12 Cells; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009414:Nerve Growth Factors; D018698:Glutamic Acid; D002118:Calcium