Depression of synaptic efficacy at intermolt in crayfish neuromuscular junctions by 20-hydroxyecdysone, a molting hormone

Journal of Neurophysiology
Robin L Cooper, M E Ruffner

Abstract

This report demonstrates that ecdysteroids can reduce synaptic transmission at an intermolt stage of a crustacean tonic neuromuscular junction by acting at a presynaptic site. The steroid molting hormone, 20-hydroxyecdysone (20-HE), appears to act through a rapid, nongenomic mechanism that decreases the probability of synaptic vesicle release and reduces the number of release sites. Quantal analysis revealed that fewer vesicles were released for a given stimulus when 20-HE was present, and this in turn accounted for the reduced synaptic efficacy. Reduced synaptic efficacy produced smaller evoked postsynaptic currents and smaller excitatory postsynaptic potentials (EPSPs) across the muscle fiber membrane. The reduction in EPSPs was observed among muscle fibers that were innervated by high- or low-output terminals. The behavior of crustaceans/crayfish during the molt cycle, when 20-HE is high, may be explained by the reduction in synaptic transmission. Crustaceans become quiescent during the premolt periods as do insects. The effects of 20-HE can be reversed with the application of the crustacean neuromodulator serotonin, which enhances synaptic transmission.

References

Jun 1, 1976·Journal of Theoretical Biology·A R Martin
Jan 1, 1991·Annals of the New York Academy of Sciences·J M WojtowiczH L Atwood
Nov 1, 1971·The Journal of Physiology·E W Johnson, A Wernig
Sep 1, 1995·Journal of Molecular Medicine : Official Organ of the Gesellschaft Deutscher Naturforscher Und Ärzte·M Wehling
Dec 12, 1995·Brain Research·R L CooperH L Atwood
Oct 3, 1996·Nature·J G Borst, B Sakmann
Jan 1, 1996·Developmental Neuroscience·J W Truman
Nov 25, 1996·The Journal of Comparative Neurology·R L CooperH L Atwood
Jun 28, 1954·The Journal of Physiology·J DEL CASTILLO, B KATZ
Oct 28, 1955·The Journal of Physiology·A R MARTIN

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Citations

Jan 23, 2003·Microscopy Research and Technique·Robin L CooperWendy M Warren
Oct 12, 2012·Experimental Neurobiology·Wen-Hui Wu, Robin L Cooper
May 23, 2015·Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology·D HydeK Bowler
Mar 10, 2000·Journal of Applied Physiology·M E Crider, R L Cooper
Mar 10, 2006·Cell and Tissue Research·J BörnerC Duch
Jan 23, 2003·Microscopy Research and Technique·Donald H EdwardsJens Herberholz
Jul 22, 2004·European Journal of Biochemistry·Mohamed ElmogySho Sakurai
Oct 3, 2008·Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology·Richard B Dewell, Jim H Belanger
Feb 9, 2013·The Journal of Experimental Biology·Julien Bacqué-CazenaveJean Paul Delbecque
Mar 26, 2002·Brain Research·Jami N Tabor, Robin L Cooper
Jul 7, 2000·Brain Research·R C SouthardR L Cooper
May 18, 1999·Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology·R L Cooper, W S Neckameyer
Sep 21, 2000·Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology·H LiR L Cooper
Apr 3, 2001·Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology·J R StrawnR L Cooper
May 29, 2000·Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology·L R ListermanR L Cooper

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