title: De novo protein synthesis of syntaxin-1 and dynamin-1 in long-term memory formation requires CREB1 gene transcription in Lymnaea stagnalis.
abstract: Consolidation of aversive operant conditioning into long-term memory (LTM) requires CREB-dependent de novo protein synthesis. The newly synthesized proteins are distributed to the synapses in neurons that are involved in memory formation and storage. Accumulating evidence indicates that the presynaptic release mechanisms also play a role in long-term synaptic plasticity. Our understanding of whether the presynaptic proteins undergo de novo synthesis during long-term memory formation is limited. In this study, we investigated the involvement of syntaxin-1, a presynaptic exocytotic protein, and dynamin-1, an endocytotic protein, in the formation of long-term memory. We took advantage of a well-established aversive operant conditioning model of aerial respiratory behavior in the fresh water pond snail Lymnaea stagnalis, and demonstrated that the LTM formation is associated with increased expression of syntaxin-1 and dynamin-1, coincident with elevated levels of CREB1. Partial knockdown of CREB1 gene by double stranded RNA inhibition (dsRNAi) prior to operant conditioning prevented snails from memory consolidation, and reduced the expression of syntaxin-1 and dynamin-1 at both mRNA and protein levels. These findings suggest that CREB1-mediated gene expression is required for the LTM-induced up-regulation of synaptic proteins, syntaxin-1 and dynamin-1, in L. stagnalis. Our study thus offers new insights into the molecular mechanisms that mediate CREB1-dependent long-term memory formation.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
authors.forename: Cong-Hui
authors.initials: CH
authors.lastname: Guo
authors.forename: Anthony
authors.initials: A
authors.lastname: Senzel
authors.forename: Kathy
authors.initials: K
authors.lastname: Li
authors.forename: Zhong-Ping
authors.initials: ZP
authors.lastname: Feng
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics* / Q000378:metabolism*; D034284:Dynamin I / Q000096:biosynthesis*; D008195:Lymnaea; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology*; D050765:Qa-SNARE Proteins / Q000096:biosynthesis*; D034622:RNA Interference / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D013569:Synapses / Q000502:physiology
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D050765:Qa-SNARE Proteins; D012333:RNA, Messenger; D000242:Cyclic AMP; D034284:Dynamin I