title: Regrowth of Serotonin Axons in the Adult Mouse Brain Following Injury.
abstract: It is widely believed that damaged axons in the adult mammalian brain have little capacity to regrow, thereby impeding functional recovery after injury. Studies using fixed tissue have suggested that serotonin neurons might be a notable exception, but remain inconclusive. We have employed in vivo two-photon microscopy to produce time-lapse images of serotonin axons in the neocortex of the adult mouse. Serotonin axons undergo massive retrograde degeneration following amphetamine treatment and subsequent slow recovery of axonal density, which is dominated by new growth with little contribution from local sprouting. A stab injury that transects serotonin axons running in the neocortex is followed by local regression of cut serotonin axons and followed by regrowth from cut ends into and across the stab rift zone. Regrowing serotonin axons do not follow the pathways left by degenerated axons. The regrown axons release serotonin and their regrowth is correlated with recovery in behavioral tests.
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA.
authors: Yunju
authors: Y
authors: Jin
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA.
authors: Sarah E
authors: SE
authors: Dougherty
authors: Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA.
authors: Kevin
authors: K
authors: Wood
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA.
authors: Landy
authors: L
authors: Sun
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA.
authors: Robert H
authors: RH
authors: Cudmore
authors: Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA.
authors: Aya
authors: A
authors: Abdalla
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA; Department of Psychiatry and Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors: Geetha
authors: G
authors: Kannan
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA; Department of Psychiatry and Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors: Mikhail
authors: M
authors: Pletnikov
authors: Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA.
authors: Parastoo
authors: P
authors: Hashemi
authors: Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, 725 North Wolfe Street, Baltimore, MD 21205, USA. Electronic address: dlinden@jhmi.edu.
authors: David J
authors: DJ
authors: Linden
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D051379:Mice; D008822:Mice, Transgenic; D019579:Neocortex / Q000166:cytology* / Q000473:pathology / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology*; D013216:Reflex, Startle / Q000502:physiology; D012183:Retrograde Degeneration / Q000139:chemically induced; D059326:Serotonergic Neurons / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D059008:Time-Lapse Imaging; D010133:p-Chloroamphetamine / Q000633:toxicity
chemical_list: D010133:p-Chloroamphetamine