title: Spontaneous transmitter release recruits postsynaptic mechanisms of long-term and intermediate-term facilitation in Aplysia.
abstract: Whereas short-term (minutes) facilitation at Aplysia sensory-motor neuron synapses is presynaptic, long-term (days) facilitation involves synaptic growth, which requires both presynaptic and postsynaptic mechanisms. How are the postsynaptic mechanisms recruited, and when does that process begin? We have been investigating the possible role of spontaneous transmitter release from the presynaptic neuron. In the previous paper, we found that spontaneous release is critical for the induction of long-term facilitation, and this process begins during an intermediate-term stage of facilitation that is the first stage to involve postsynaptic as well as presynaptic mechanisms. We now report that increased spontaneous release during the short-term stage acts as an orthograde signal to recruit postsynaptic mechanisms of intermediate-term facilitation including increased IP3, Ca(2+), and membrane insertion and recruitment of clusters of AMPA-like receptors, which may be first steps in synaptic growth during long-term facilitation. These results suggest that the different stages of facilitation involve a cascade of pre- and postsynaptic mechanisms, which is initiated by spontaneous release and may culminate in synaptic growth.
authors.affiliation: Department of Neuroscience, Columbia University, New York, NY 10032, USA.
authors.forename: Iksung
authors.initials: I
authors.lastname: Jin
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Udo
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Rayman
authors.forename: Sathya
authors.initials: S
authors.lastname: Puthanveettil
authors.forename: Eric R
authors.initials: ER
authors.lastname: Kandel
authors.forename: Robert D
authors.initials: RD
authors.lastname: Hawkins
mesh_terms: D000818:Animals; D001048:Aplysia; D001905:Botulinum Toxins; D002118:Calcium / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives; D005453:Fluorescence; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D006921:Hygromycin B; D017403:In Situ Hybridization; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D009473:Neuronal Plasticity; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009655:Octopamine; D009841:Oligonucleotides / Q000235:genetics; D009930:Organic Chemicals; D010957:Plasmids / Q000235:genetics; D017729:Presynaptic Terminals / Q000378:metabolism / Q000502:physiology; D018091:Receptors, AMPA / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; D018377:Neurotransmitter Agents; D009841:Oligonucleotides; D009930:Organic Chemicals; D018091:Receptors, AMPA; D018094:Receptors, Metabotropic Glutamate; C071335:calcium orange; D009655:Octopamine; C096325:botulinum toxin type D; D006921:Hygromycin B; D004533:Egtazic Acid; D001905:Botulinum Toxins; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium