title: The FMRFamide-related neuropeptide FLP-20 is required in the mechanosensory neurons during memory for massed training in C. elegans.
abstract: Lasting memories are likely to result from a lasting change in neurotransmission. In the nematode Caenorhabditis elegans, spaced training with a tap stimulus induces habituation to the tap that lasts for >24 h and is dependent on glutamate transmission, postsynaptic AMPA receptors, and CREB. Here we describe a distinct, presynaptic mechanism for a shorter lasting memory for tap habituation induced by massed training. We report that a FMRFamide-related peptide (FMRF = Phe-Met-Arg-Phe-NH(2)), FLP-20, is critical for memory lasting 12 h following massed training, but is not required for other forms of memory. Massed training correlated with a flp-20-dependent increase in synaptobrevin tagged with green fluorescent protein in the presynaptic terminals of the PLM mechanosensory neurons that followed the timeline of the memory trace. We also demonstrated that flp-20 is required specifically in the mechanosensory neurons for memory 12 h after massed training. These findings show that within the same species and form of learning, memory is induced by distinct mechanisms to create a lasting alteration in neurotransmission that is dependent upon the temporal pattern of training: memory of spaced training results from postsynaptic changes in the interneurons of the neural circuit, whereas memory of massed training results from presynaptic changes in the mechanosensory neurons of the neural circuit.
authors: Department of Biology, City College of the City University of New York, NY 10031, USA. cli@sci.ccny.cuny.edu
authors: Chris
authors: C
authors: Li
authors: Tiffany A
authors: TA
authors: Timbers
authors: Jacqueline K
authors: JK
authors: Rose
authors: Tahereh
authors: T
authors: Bozorgmehr
authors: Andrea
authors: A
authors: McEwan
authors: Catharine H
authors: CH
authors: Rankin
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D019835:FMRFamide / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D007858:Learning / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects / Q000235:genetics; D008465:Mechanoreceptors / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D009154:Mutation / Q000235:genetics; D009479:Neuropeptides / Q000235:genetics; D013028:Space Perception / Q000502:physiology; D013997:Time Factors
chemical_list: D029742:Caenorhabditis elegans Proteins; D009479:Neuropeptides; D049452:Green Fluorescent Proteins; D019835:FMRFamide