title: Synaptic dynamism measured over minutes to months: age-dependent decline in an autonomic ganglion.
abstract: Naturally occurring rearrangements of synaptic terminals are common in the nervous systems of young mammals, but little is known about their incidence in adults. Using transgenic mice that express yellow fluorescent protein (YFP) in axons, we repeatedly imaged nerve terminals in the parasympathetic submandibular ganglion. We found that the pattern of synaptic branches underwent significant rearrangements over several weeks in young adult mice. In older mice, rearrangements were less common, and synaptic patterns on individual neurons were recognizable for many months to years. Axonal branches frequently retracted or extended on a time scale of minutes in young adult mice, but seldom in mature animals. These results provide direct evidence for a decrease in plasticity of interneuronal connections as animals make the transition from young adulthood to middle age. The long-term stability of synaptic patterns could provide a structural basis for the persistence of memory in the adult nervous system.
authors.affiliation: Department of Anatomy & Neurobiology, Washington University School of Medicine, 660 South Euclid, Box 8108, St. Louis, Missouri 63110, USA.
authors.forename: Wen-Biao
authors.initials: WB
authors.lastname: Gan
authors.forename: Elaine
authors.initials: E
authors.lastname: Kwon
authors.forename: Guoping
authors.initials: G
authors.lastname: Feng
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Sanes
authors.forename: Jeff W
authors.initials: JW
authors.lastname: Lichtman
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis; D005725:Ganglia, Autonomic / Q000737:chemistry / Q000254:growth & development*; D008164:Luminescent Proteins / Q000032:analysis / Q000096:biosynthesis; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal / Q000379:methods; D017729:Presynaptic Terminals / Q000737:chemistry / Q000502:physiology*; D013569:Synapses / Q000737:chemistry / Q000502:physiology*; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria