title: Characterization of NO-sensitive guanylyl cyclase: expression in an identified interneuron involved in NO-cGMP-dependent memory formation.
abstract: In a number of neuronal models of learning signalling by endogenous nitric oxide (NO), produced by the enzyme NO synthase (NOS), is essential for the formation of long-term memory (LTM). For example, in the molluscan model system Lymnaea, NO is required for LTM formation in the first few hours after one-trial reward conditioning. Furthermore, conditioning leads to transient up-regulation of the NOS gene in identified modulatory neurons, the cerebral giant cells (CGCs), which are known to be involved in LTM formation. In Lymnaea nothing is known however about the structure and localization of the major receptor for NO, the soluble guanylyl cyclase (sGC). Here we report on the cloning and characterization of both alpha and beta subunits of NO-sensitive sGC and show that they are coexpressed in the CGCs. Furthermore, our electrophysiological experiments on isolated CGCs show that these neurons respond to NO by generating a prolonged depolarization of the membrane potential. Moreover, we demonstrate that this depolarization is blocked by ODQ, supporting our hypothesis that it is mediated by sGC.
authors.affiliation: Department of Biology and Environmental Science, School of Life Sciences, Sussex Centre for Neuroscience, University of Sussex, Brighton, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Ribeiro
authors.forename: Volko A
authors.initials: VA
authors.lastname: Straub
authors.forename: Michael
authors.initials: M
authors.lastname: Schofield
authors.forename: Jo
authors.initials: J
authors.lastname: Picot
authors.forename: Paul R
authors.initials: PR
authors.lastname: Benjamin
authors.forename: Michael
authors.initials: M
authors.lastname: O'Shea
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Korneev
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism*; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000378:metabolism; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008195:Lymnaea / Q000201:enzymology; D008568:Memory / Q000502:physiology*; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D010069:Oxadiazoles / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D011810:Quinoxalines / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D000071756:Soluble Guanylyl Cyclase
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D019476:Insect Proteins; D010069:Oxadiazoles; D021122:Protein Subunits; D011810:Quinoxalines; D018160:Receptors, Cytoplasmic and Nuclear; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP