title: Activity-dependent alteration of the morphology of a hippocampal giant synapse.
abstract: Activity-dependent synaptic plasticity is a fundamental cellular process for learning and memory. While electrophysiological plasticity has been intensively studied, morphological plasticity is less clearly understood. This study investigated the effect of presynaptic stimulation on the morphology of a giant mossy fiber-CA3 pyramidal cell synapse, and found that the mossy fiber bouton altered its morphology with an increase in the number of segments. This activity-dependent alteration in morphology required the activation of glutamate receptors and an increase in postsynaptic calcium concentration. In addition, the intercellular retrograde messengers nitric oxide and arachidonic acid were necessary. Simultaneous recordings demonstrated that the morphological complexity of the presynaptic bouton and the amplitude of excitatory postsynaptic currents were well correlated. Thus, a single mossy fiber synapse has the potential for activity-dependent morphological plasticity at the presynaptic bouton, which may be important for learning and memory.
authors.affiliation: Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Maruo
authors.affiliation: Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Mandai
authors.affiliation: Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan. Electronic address: ytakai@med.kobe-u.ac.jp.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Division of Neurophysiology, Department of Cellular Physiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; Faculty of Health Sciences, Kobe University Graduate School of Health Sciences, 7-10-2, Tomogaoka, Suma-ku, Kobe 654-0142, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan. Electronic address: mori@gold.kobe-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mori
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D056654:CA3 Region, Hippocampal / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D019706:Excitatory Postsynaptic Potentials; D051379:Mice; D008810:Mice, Inbred C57BL; D019599:Mossy Fibers, Hippocampal / Q000378:metabolism / Q000502:physiology*; D009473:Neuronal Plasticity; D009569:Nitric Oxide / Q000378:metabolism; D017966:Pyramidal Cells / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D017470:Receptors, Glutamate / Q000378:metabolism
chemical_list: D017470:Receptors, Glutamate; D016718:Arachidonic Acid; D009569:Nitric Oxide; D002118:Calcium
keywords: Hippocampus; Mossy fiber; Synaptic morphology; Synaptic plasticity