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A Simple Mathematical Model of Second-Messenger Mediated Slow Excitatory Postsynaptic Potentials

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Abstract

We have developed a novel and simple mathematical model of a slow excitatory postsynaptic potential (EPSP) based on an abstraction of the processes of activation, inactivation, and summation of a cAMP, protein kinase A (PKA)-dependent second-messenger cascade. The model describes the activation of receptors, G-proteins, and production of cAMP as the first stage and uses first-order, non-rate-limited kinetics. The second stage corresponds to the release of active, PKA catalytic subunit and can use first- or higher-order kinetics. The third stage represents simple phosphorylation of ion channels and is limited by the number of channels available. The decay of each stage is based on first-order, mass-action kinetics. These equations and some variations were solved numerically and values of the parameters were determined by fitting to a variety of experimental data from myenteric neurons of the guinea-pig ileum. The model produced a slow EPSP with a nonlinear stimulus-response relationship that resulted from the underlying kinetics of the signaling cascade. This system of equations is suitable for incorporation into a large-scale computer simulation, and the methodology should be generalizable to other pathways.

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References

  • Acton SF (1970) Numerical Methods That Work. Harper & Row, New York.

    Google Scholar 

  • Akasu T, Tokimasa T (1989) Potassium currents in submucous neurones of guinea-pig caecum and their synaptic modification. J. Physiol. 416:571–588.

    PubMed  Google Scholar 

  • Baidan LV, Fertel RH, Wood JD (1992) Effects of brain-gut related peptides on cAMP levels in myenteric ganglia of guinea-pig small intestine. Eur. J. Pharmacol. 225:21–27.

    PubMed  Google Scholar 

  • Bennett MR, Gibson WG (1995) On the contribution of quantal secretion from close-contact and loose-contact varicosities to the synaptic potentials in the vas deferens. Phil. Trans. Royal Soc. Lond. 347:187–204.

    Google Scholar 

  • Bertrand PP, Galligan JJ (1994) Contribution of chloride conductance increase to slow EPSC and tachykinin current in guinea-pig myenteric neurones. J. Physiol. 481:47–60.

    PubMed  Google Scholar 

  • Bertrand PP, Galligan JJ (1995) Signal-transduction pathways causing slow synaptic excitation in guinea pig myenteric AH neurons. Am. J. Physiol. 269:G710-G720.

    PubMed  Google Scholar 

  • Bornstein JC, Furness JB, Kelly HF, Bywater RA, Neild TO, Bertrand PP (1997) Computer simulation of the enteric neural circuits mediating an ascending reflex: Roles of fast and slow excitatory outputs of sensory neurons. J. Autonomic Nervous Sys. 64:143–157.

    Google Scholar 

  • Builder SE, Beavo JA, Krebs, EG (1980) Stoichiometry of cAMP and 1,N6-etheno-cAMP binding to protein kinase. J. Biol. Chem. 255:2350–2354.

    PubMed  Google Scholar 

  • Buxbaum JD, Dudai Y (1989) A quantitative model for the kinetics of cAMP-dependent protein kinase (Type II) activity. J. Biol. Chem. 264:9344–9351.

    PubMed  Google Scholar 

  • Carman CV, Benovic JL (1998) G-protein-coupled receptors: Turnons and turn-offs. Current Opinions in Neurobiol. 8:335–344.

    Google Scholar 

  • Clapham DE, Neer EJ (1997)G protein αγ subunits. Ann. Rev. Pharmacol. and Toxicol. 37:167–203.

    Google Scholar 

  • Clerc N, Furness JB, Kunze WAA, Thomas EA and Bertrand PP (1999) Long-term effects of synaptic activation at low frequency on excitability of myenteric AH neurons. Neurosci. 90:277–278.

    Google Scholar 

  • Destexhe A, Mainen ZF, Sejnowski TJ (1994) Synthesis of models for excitable membranes, synaptic transmission and neuromodulation using a common kinetic formalism. J. Comput. Neurosci. 1:195–230.

    PubMed  Google Scholar 

  • Destexshe A, Sejnowski TJ (1995) G protein activation kinetics and spillover of gamma-aminobutyric acid may account for differences between inhibitory responses in the hippocampus and thalamus. Proc. Natl. Acad. Sci. (USA) 92:9515–9519.

    Google Scholar 

  • Furness JB, Costa M (1987) The Enteric Nervous System. Churchill Livingston, Edinburgh.

    Google Scholar 

  • Galligan JJ, Tokimasa T, North RA (1987) Effects of three mammalian tachykinins on single enteric neurons. Neurosci. Letters 82:167–171.

    Google Scholar 

  • Gray PC, Scott JD, Catterall WA (1998) Regulation of ion channels by cAMP-dependent protein kinase and A-kinase anchoring protein. Current Opinion in Neurobiol. 8:330–334.

    Google Scholar 

  • Hempel CM, Vincent P, Adams SR, Tsien RY, Selverston AI (1996) Spatio-temporal dynamics of cyclic AMP signals in an intact neural circuit. Nature 384:166–169.

    PubMed  Google Scholar 

  • Hille B (1992) Ionic Channels of Excitable Membranes (2nd ed.) Sinauer Associates, Sunderland, MA.

    Google Scholar 

  • Johnson PJ, Bornstein JC, Burcher E (1998) Roles of neuronal NK1 and NK3 receptors in synaptic transmission during motility reflexes in the guinea-pig ileum. Br. J. Pharmacol. 124 (7):1375–1384.

    PubMed  Google Scholar 

  • Katayama Y, North RA (1978) Does substance P mediate slow synaptic excitation within the myenteric plexus? Nature 274:387–388.

    PubMed  Google Scholar 

  • Kunze WAA, Furness JB, Bornstein JC (1993) Simultaneous intracellular recordings from enteric neurons reveal that myenteric AH neurons transmit via slow excitatory postsynaptic potentials. Neurosci. 55:685–694.

    Google Scholar 

  • Kunze WAA, Bertrand PP, Furness JB, Bornstein JC (1997) Influence of the mucosa on the excitability of myenteric neurons. Neurosci. 76:619–634.

    Google Scholar 

  • Kunze WAA, Furness JB (1999). The enteric nervous system and regulation of intestinal motility. Ann. Rev. Physiol. 61:117–124.

    Google Scholar 

  • Lamb TD (1996) Gain and kinetics of activation in the G-protein cascade of phototransduction. Proc. Nat. Acad. Sci. 93:556–570.

    Google Scholar 

  • Lamb TD, Pugh EN (1992) A quantitative account of the activation steps involved in phototransduction in amphibian photoreceptors. J. Physiol. 449:719–758.

    PubMed  Google Scholar 

  • Morita K, Katayama K (1992) Substance P inhibits activation of calcium-dependent potassium conductances in guinea-pig myenteric neurones. J. Physiol. 447:293–308.

    PubMed  Google Scholar 

  • Morita K, North RA (1985) Significance of slow synaptic potentials for transmission of excitation in guinea-pig myenteric plexus. Neurosci. 14:661–672.

    Google Scholar 

  • Nauroschat J, an der Heiden U (1997) A theoretical approach to Gprotein modulation of cellular responsiveness. Math. Biol. 35:609–627.

    Google Scholar 

  • Nemeth PR, Palmer JM, Wood JD, Zafirov DH (1986) Effects of forskolin on electrical behaviour of myenteric neurones in guineapig small intestine. J. Physiol. 376:439–450.

    PubMed  Google Scholar 

  • Pan H, Wang HY, Friedman E, Gershon MD (1997) Mediation by protein kinases C and A of Go-linked slow responses of enteric neurons to 5-HT. J. Neurosci. 17:1011–1024

    PubMed  Google Scholar 

  • Press WH, Teukolsky SA, Vetterling WT, Flannery BP (1992) Numerical Recipes in C: The Art of Scientific Computing (2nd ed.). Cambridge University Press, Cambridge.

    Google Scholar 

  • Ross EM (1989) Signal sorting and amplification through G protein-coupled receptors. Neuron 3:141–152.

    PubMed  Google Scholar 

  • Southwell BR, Woodman HL, Murphy R, Royal SJ, Furness JB (1996) Characterisation of substance P-induced endocytosis of NK1 receptors on enteric neurons. Histochem. and Cell Biol. 106:563–571.

    Google Scholar 

  • Taylor SS (1989) cAMP-dependent protein kinase: Model for an enzyme family. J. Biol. Chem. 264:8443–8446.

    PubMed  Google Scholar 

  • Thomas EA, Bertrand PP, Bornstein JC (1999) Genesis and role of coordinated firing in a feed forward network: A model study of the enteric nervous system. Neurosci. 93:1525--.

    Google Scholar 

  • Torre V, Ashmore JF, Lamb TD, Menini A (1995) Transduction and adaptation in sensory receptor cells. J. Neurosci. 15:7757–7768.

    PubMed  Google Scholar 

  • Vergara C, Latorre R, Marrion NV, Adelman JP (1998) Calcium-activated potassium channels. Current Opinions in Neurobiol. 8(3):321–329.

    Google Scholar 

  • Wood JD (1994) Physiology of the enteric nervous system. In: Johnson LR, ed. Physiology of the Gastrointestinal Tract. Raven Press, New York. pp. 423–482.

    Google Scholar 

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Bertrand, P., Thomas, E., Kunze, W. et al. A Simple Mathematical Model of Second-Messenger Mediated Slow Excitatory Postsynaptic Potentials. J Comput Neurosci 8, 127–142 (2000). https://doi.org/10.1023/A:1008969115017

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