title: A lysolecithin/fatty acid mixture promotes and then blocks neurotransmitter release at the Drosophila melanogaster larval neuromuscular junction.
abstract: The study of the effect of snake presynaptic neurotoxins with phospholipase A2 activity on nerve terminals has recently unveiled the inhibitory action of a lysophosphatidylcholine (LysoPC)/fatty acid mixture. We report here that these neurotoxins have no activity on Drosophila melanogaster nerve terminals. However, a 1:1 mixture of LysoPC and oleic acid induces an early increase, followed by an inhibition of both evoked and spontaneous neurotransmitter release. This effect is also induced by LysoPC alone. The present findings provide an indirect evidence that the lipid hemifusion-to-pore transition is a key event in neuroexocytosis in Drosophila. Moreover, these findings substantiate the use of LysoPC as a general agonist of membrane fusion at nerve terminals. This novel tool could contribute to the unraveling of the molecular steps involved in neuroexocytosis, particularly in Drosophila, where it is straightforward to combine it with electrophysiology and genetics.
authors.affiliation: Department of Human Anatomy and Physiology, Section of Physiology, University of Padova, Via Marzolo 3, Padova, Italy. aram.megighian@unipd.it
authors.forename: Aram
authors.initials: A
authors.lastname: Megighian
authors.forename: Michela
authors.initials: M
authors.lastname: Rigoni
authors.forename: Paola
authors.initials: P
authors.lastname: Caccin
authors.forename: Mauro A
authors.initials: MA
authors.lastname: Zordan
authors.forename: Cesare
authors.initials: C
authors.lastname: Montecucco
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster; D004594:Electrophysiology; D004705:Endocytosis / Q000187:drug effects*; D005071:Evoked Potentials / Q000187:drug effects; D005089:Exocytosis / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008561:Membrane Fusion / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism*; D019301:Oleic Acid / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D008244:Lysophosphatidylcholines; D018377:Neurotransmitter Agents; D019301:Oleic Acid