title: Cyclic AMP inhibits neuromuscular junction maturation mediated by intracellular Ca2+.
abstract: The neuromuscular junction (NMJ) is established through initial contact of motor neuron axon with a skeletal muscle cell and the subsequent synaptic maturation. Previous studies have shown that cyclic AMP (cAMP) enhanced spinal neurons' survival and growth but inhibited synaptogenesis. Here, we find that elevating intracellular cAMP level of presynaptic neurons prevented NMJs from maturation both physiologically and morphologically. Importantly, cytosolic Ca(2+) is essential for the inhibitory effects of cAMP on NMJ maturation. We show that depletion of intracellular Ca(2+) store, rather than extracellular Ca(2+), abolished the cAMP-dependent inhibition of synaptic maturation. Taken together, we demonstrate that Ca(2+) released from intracellular Ca(2+) stores regulates neurotrophic actions on NMJ maturation.
authors.affiliation: Peking University Health Science Center, Beijing 100191, China; Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China. Electronic address: sw@hsc.pku.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.affiliation: Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China. Electronic address: albertxiwanjin@gmail.com.
authors.forename: Xiwan Albert
authors.initials: XA
authors.lastname: Jin
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism* / Q000494:pharmacology; D042541:Intracellular Space / Q000378:metabolism; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D055366:Synaptic Potentials; D014981:Xenopus
chemical_list: D000242:Cyclic AMP; D002118:Calcium
keywords: Ca(2+); Cyclic AMP; Synaptic maturation