Effects of nitric oxide on neuromuscular properties of developing zebrafish embryos.
Nitric oxide is a bioactive signalling molecule that is known to affect a wide range of neurodevelopmental processes. However, its functional relevance to neuromuscular development is not fully understood. Here we have examined developmental roles of nitric oxide during formation and maturation of neuromuscular contacts in zebrafish. Using histochemical approaches we show that elevating nitric oxide levels reduces the number of neuromuscular synapses within the axial swimming muscles whilst inhibition of nitric oxide biosynthesis has the opposite effect. We further show that nitric oxide signalling does not change synapse density, suggesting that the observed effects are a consequence of previously reported changes in motor axon branch formation. Moreover, we have used in vivo patch clamp electrophysiology to examine the effects of nitric oxide on physiological maturation of zebrafish neuromuscular junctions. We show that developmental exposure to nitric oxide affects the kinetics of spontaneous miniature end plate currents and impacts the neuromuscular drive for locomotion. Taken together, our findings implicate nitrergic signalling in the regulation of zebrafish neuromuscular development and locomotor maturation.
University of Leicester, Department of Biology, College of Medicine, Biological Sciences and Psychology, Leicester, United Kingdom.
Michael
M
Jay
University of Leicester, Department of Biology, College of Medicine, Biological Sciences and Psychology, Leicester, United Kingdom.
Sophie
S
Bradley
University of Leicester, Department of Biology, College of Medicine, Biological Sciences and Psychology, Leicester, United Kingdom.
Jonathan Robert
JR
McDearmid
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000502:physiology*; D047108:Embryonic Development / Q000187:drug effects; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007700:Kinetics; D008124:Locomotion / Q000187:drug effects; D055369:Miniature Postsynaptic Potentials / Q000187:drug effects; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000196:embryology* / Q000502:physiology*; D009569:Nitric Oxide / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D015398:Signal Transduction / Q000187:drug effects; D013550:Swimming; D015027:Zebrafish / Q000196:embryology*
D015415:Biomarkers; C119129:18alpha-glycyrrhetinic acid; D009569:Nitric Oxide; D006152:Cyclic GMP; D006034:Glycyrrhetinic Acid