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Inactivity-induced increase in nAChRs upregulates Shal K+ channels to stabilize synaptic potentials

Abstract

Long-term synaptic changes, which are essential for learning and memory, are dependent on homeostatic mechanisms that stabilize neural activity. Homeostatic responses have also been implicated in pathological conditions, including nicotine addiction. Although multiple homeostatic pathways have been described, little is known about how compensatory responses are tuned to prevent them from overshooting their optimal range of activity. We found that prolonged inhibition of nicotinic acetylcholine receptors (nAChRs), the major excitatory receptors in the Drosophila CNS, resulted in a homeostatic increase in the Drosophila α7 (Dα7)-nAChR. This response then induced an increase in the transient A-type K+ current carried by Shaker cognate L (Shal; also known as voltage-gated K+ channel 4, Kv4) channels. Although increasing Dα7-nAChRs boosted miniature excitatory postsynaptic currents, the ensuing increase in Shal channels served to stabilize postsynaptic potentials. These data identify a previously unknown mechanism for fine tuning the homeostatic response.

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Figure 1: Synaptic blockade induced an increase in Dα7 receptors.
Figure 2: Inactivity resulted in an increase in Shal channels, preferentially in dendrites, following recovery of synaptic transmission.
Figure 3: Dα7 and Shal proteins were increased at the translational and transcriptional level, respectively.
Figure 4: Dα7 receptors were essential for the increased expression of Shal channels.
Figure 5: Ca2+ influx through Dα7 receptors was required for the increase in Shal channels.
Figure 6: Activation of CaMKII, but not CaMKK, was required for the increase in Shal channel expression.
Figure 7: Higher number of Shal channels stabilized synaptic potentials.

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References

  1. Turrigiano, G. Too many cooks? Intrinsic and synaptic homeostatic mechanisms in cortical circuit refinement. Annu. Rev. Neurosci. 34, 89–103 (2011).

    Article  CAS  Google Scholar 

  2. Davis, G.W. Homeostatic control of neural activity: from phenomenology to molecular design. Annu. Rev. Neurosci. 29, 307–323 (2006).

    Article  CAS  Google Scholar 

  3. Pozo, K. & Goda, Y. Unraveling mechanisms of homeostatic synaptic plasticity. Neuron 66, 337–351 (2010).

    Article  CAS  Google Scholar 

  4. Desai, N.S., Rutherford, L.C. & Turrigiano, G.G. Plasticity in the intrinsic excitability of cortical pyramidal neurons. Nat. Neurosci. 2, 515–520 (1999).

    Article  CAS  Google Scholar 

  5. Kuba, H., Oichi, Y. & Ohmori, H. Presynaptic activity regulates Na+ channel distribution at the axon initial segment. Nature 465, 1075–1078 (2010).

    Article  CAS  Google Scholar 

  6. Baines, R.A., Uhler, J.P., Thompson, A., Sweeney, S.T. & Bate, M. Altered electrical properties in Drosophila neurons developing without synaptic transmission. J. Neurosci. 21, 1523–1531 (2001).

    Article  CAS  Google Scholar 

  7. Nataraj, K., Le Roux, N., Nahmani, M., Lefort, S. & Turrigiano, G. Visual deprivation suppresses L5 pyramidal neuron excitability by preventing the induction of intrinsic plasticity. Neuron 68, 750–762 (2010).

    Article  CAS  Google Scholar 

  8. De Biasi, M. & Dani, J.A. Reward, addiction, withdrawal to nicotine. Annu. Rev. Neurosci. 34, 105–130 (2011).

    Article  CAS  Google Scholar 

  9. Picciotto, M.R., Addy, N.A., Mineur, Y.S. & Brunzell, D.H. It is not “either/or”: activation and desensitization of nicotinic acetylcholine receptors both contribute to behaviors related to nicotine addiction and mood. Prog. Neurobiol. 84, 329–342 (2008).

    Article  CAS  Google Scholar 

  10. Fenster, C.P., Whitworth, T.L., Sheffield, E.B., Quick, M.W. & Lester, R.A. Upregulation of surface α4β2 nicotinic receptors is initiated by receptor desensitization after chronic exposure to nicotine. J. Neurosci. 19, 4804–4814 (1999).

    Article  CAS  Google Scholar 

  11. Tsunoda, S. & Salkoff, L. The major delayed rectifier in both Drosophila neurons and muscle is encoded by Shab. J. Neurosci. 15, 5209–5221 (1995b).

    Article  CAS  Google Scholar 

  12. Tsunoda, S. & Salkoff, L. Genetic analysis of Drosophila neurons: Shal, Shaw, and Shab encode most embryonic potassium currents. J. Neurosci. 15, 1741–1754 (1995a).

    Article  CAS  Google Scholar 

  13. Lee, D. & O'Dowd, D.K. Fast excitatory synaptic transmission mediated by nicotinic acetylcholine receptors in Drosophila neurons. J. Neurosci. 19, 5311–5321 (1999).

    Article  CAS  Google Scholar 

  14. Leung, H.T., Branton, W.D., Phillips, H.S., Jan, L. & Byerly, L. Spider toxins selectively block calcium currents in Drosophila. Neuron 3, 767–772 (1989).

    Article  CAS  Google Scholar 

  15. Ping, Y. et al. Shal/Kv4 channels are required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. PLoS ONE 6, e16043 (2011).

    Article  CAS  Google Scholar 

  16. Su, H. & O'Dowd, D.K. Fast synaptic currents in Drosophila mushroom body Kenyon cells are mediated by α-bungarotoxin-sensitive nicotinic acetylcholine receptors and picrotoxin-sensitive GABA receptors. J. Neurosci. 23, 9246–9253 (2003).

    Article  CAS  Google Scholar 

  17. Schmidt, H. et al. The embryonic central nervous system lineages of Drosophila melanogaster. II. Neuroblast lineages derived from the dorsal part of the neuroectoderm. Dev. Biol. 189, 186–204 (1997).

    Article  CAS  Google Scholar 

  18. Gotti, C. et al. Structural and functional diversity of native brain neuronal nicotinic receptors. Biochem. Pharmacol. 78, 703–711 (2009).

    Article  CAS  Google Scholar 

  19. Albuquerque, E.X., Pereira, E.F., Alkondon, M. & Rogers, S.W. Mammalian nicotinic acetylcholine receptors: from structure to function. Physiol. Rev. 89, 73–120 (2009).

    Article  CAS  Google Scholar 

  20. Aracava, Y., Pereira, E.F., Maelicke, A. & Albuquerque, E.X. Memantine blocks α7* nicotinic acetylcholine receptors more potently than N-methyl-D-aspartate receptors in rat hippocampal neurons. J. Pharmacol. Exp. Ther. 312, 1195–1205 (2005).

    Article  CAS  Google Scholar 

  21. Brickley, S.G., Revilla, V., Cull–Candy, S.G., Wisden, W. & Farrant, M. Adaptive regulation of neuronal excitability by a voltage-independent potassium conductance. Nature 409, 88–92 (2001).

    Article  CAS  Google Scholar 

  22. Pulver, S.R. & Griffith, L.C. Spike integration and cellular memory in a rhythmic network from Na+/K+ pump current dynamics. Nat. Neurosci. 13, 53–59 (2010).

    Article  CAS  Google Scholar 

  23. Grauso, M., Reenan, R.A., Culetto, E. & Sattelle, D.B. Novel putative nicotinic acetylcholine receptor subunit genes, Dα5, Dα6 and Dα7, in Drosophila melanogaster identify a new and highly conserved target of adenosine deaminase acting on RNA-mediated A-to-I pre-mRNA editing. Genetics 160, 1519–1533 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Griffith, L.C. et al. Inhibition of calcium/calmodulin-dependent protein kinase in Drosophila disrupts behavioral plasticity. Neuron 10, 501–509 (1993).

    Article  CAS  Google Scholar 

  25. Tripodi, M., Evers, J.F., Mauss, A., Bate, M. & Landgraf, M. Structural homeostasis: compensatory adjustments of dendritic arbor geometry in response to variations of synaptic input. PLoS Biol. 6, e260 (2008).

    Article  Google Scholar 

  26. Kremer, M.C. et al. Structural long-term changes at mushroom body input synapses. Curr. Biol. 20, 1938–1944 (2010).

    Article  CAS  Google Scholar 

  27. Bushey, D., Tononi, G. & Cirelli, C. Sleep and synaptic homeostasis: structural evidence in Drosophila. Science 332, 1576–1581 (2011).

    Article  CAS  Google Scholar 

  28. Chou, Y.H. et al. Diversity and wiring variability of olfactory local interneurons in the Drosophila antennal lobe. Nat. Neurosci. 13, 439–449 (2010).

    Article  CAS  Google Scholar 

  29. Lichtman, J.W. & Colman, H. Synapse elimination and indelible memory. Neuron 25, 269–278 (2000).

    Article  CAS  Google Scholar 

  30. Small, D.H. Network dysfunction in Alzheimer's disease: does synaptic scaling drive disease progression? Trends Mol. Med. 14, 103–108 (2008).

    Article  CAS  Google Scholar 

  31. Jerng, H.H., Pfaffinger, P.J. & Covarrubias, M. Molecular physiology and modulation of somatodendritic A-type potassium channels. Mol. Cell. Neurosci. 27, 343–369 (2004).

    Article  CAS  Google Scholar 

  32. Chen, X. et al. Deletion of Kv4.2 gene eliminates dendritic A-type K+ current and enhances induction of long-term potentiation in hippocampal CA1 pyramidal neurons. J. Neurosci. 26, 12143–12151 (2006).

    Article  CAS  Google Scholar 

  33. Kim, J., Jung, S.C., Clemens, A.M., Petralia, R.S. & Hoffman, D.A. Regulation of dendritic excitability by activity-dependent trafficking of the A-type K+ channel subunit Kv4.2 in hippocampal neurons. Neuron 54, 933–947 (2007).

    Article  CAS  Google Scholar 

  34. Cai, X. et al. Unique roles of SK and Kv4.2 potassium channels in dendritic integration. Neuron 44, 351–364 (2004).

    Article  CAS  Google Scholar 

  35. Thiagarajan, T.C., Piedras–Renteria, E.S. & Tsien, R.W. α- and β-CaMKII. Inverse regulation by neuronal activity and opposing effects on synaptic strength. Neuron 36, 1103–1114 (2002).

    Article  CAS  Google Scholar 

  36. Groth, R.D., Lindskog, M., Thiagarajan, T.C., Li, L. & Tsien, R.W. β Ca2+/CaM-dependent kinase type II triggers upregulation of GluA1 to coordinate adaptation to synaptic inactivity in hippocampal neurons. Proc. Natl. Acad. Sci. USA 108, 828–833 (2011).

    Article  CAS  Google Scholar 

  37. Varga, A.W. et al. Calcium–calmodulin-dependent kinase II modulates Kv4.2 channel expression and upregulates neuronal A-type potassium currents. J. Neurosci. 24, 3643–3654 (2004).

    Article  CAS  Google Scholar 

  38. Misonou, H. Homeostatic regulation of neuronal excitability by K+ channels in normal and diseased brains. Neuroscientist 16, 51–64 (2010).

    Article  CAS  Google Scholar 

  39. Magee, J.C. & Cook, E.P. Somatic EPSP amplitude is independent of synapse location in hippocampal pyramidal neurons. Nat. Neurosci. 3, 895–903 (2000).

    Article  CAS  Google Scholar 

  40. Hoffman, D.A., Magee, J.C., Colbert, C.M. & Johnston, D. K+ channel regulation of signal propagation in dendrites of hippocampal pyramidal neurons. Nature 387, 869–875 (1997).

    Article  CAS  Google Scholar 

  41. Kazama, H. & Wilson, R.I. Homeostatic matching and nonlinear amplification at identified central synapses. Neuron 58, 401–413 (2008).

    Article  CAS  Google Scholar 

  42. Fujioka, M. et al. Even-skipped, acting as a repressor, regulates axonal projections in Drosophila. Development 130, 5385–5400 (2003).

    Article  CAS  Google Scholar 

  43. Fayyazuddin, A., Zaheer, M.A., Hiesinger, P.R. & Bellen, H.J. The nicotinic acetylcholine receptor Dα7 is required for an escape behavior in Drosophila. PLoS Biol. 4, e63 (2006).

    Article  Google Scholar 

  44. Watson, G.B. et al. A spinosyn–sensitive Drosophila melanogaster nicotinic acetylcholine receptor identified through chemically induced target site resistance, resistance gene identification, and heterologous expression. Insect Biochem. Mol. Biol. 40, 376–384 (2010).

    Article  CAS  Google Scholar 

  45. Hegde, P., Gu, G.G., Chen, D., Free, S.J. & Singh, S. Mutational analysis of the Shab-encoded delayed rectifier K(+) channels in Drosophila. J. Biol. Chem. 274, 22109–22113 (1999).

    Article  CAS  Google Scholar 

  46. Diao, F., Waro, G. & Tsunoda, S. Fast inactivation of Shal (Kv4) K+ channels is regulated by the novel interactor SKIP3 in Drosophila neurons. Mol. Cell. Neurosci. 42, 33–44 (2009).

    Article  CAS  Google Scholar 

  47. Schulz, R. et al. Neuronal nicotinic acetylcholine receptors from Drosophila: two different types of alpha subunits coassemble within the same receptor complex. J. Neurochem. 74, 2537–2546 (2000).

    Article  CAS  Google Scholar 

  48. Jonas, P.E., Phannavong, B., Schuster, R., Schroder, C. & Gundelfinger, E.D. Expression of the ligand-binding nicotinic acetylcholine receptor subunit Dα2 in the Drosophila central nervous system. J. Neurobiol. 25, 1494–1508 (1994).

    Article  CAS  Google Scholar 

  49. Chamaon, K., Schulz, R., Smalla, K.H., Seidel, B. & Gundelfinger, E.D. Neuronal nicotinic acetylcholine receptors of Drosophila melanogaster: the α-subunit Dα3 and the β-type subunit ARD co–assemble within the same receptor complex. FEBS Lett. 482, 189–192 (2000).

    Article  CAS  Google Scholar 

  50. Chamaon, K., Smalla, K.H., Thomas, U. & Gundelfinger, E.D. Nicotinic acetylcholine receptors of Drosophila: three subunits encoded by genomically linked genes can co–assemble into the same receptor complex. J. Neurochem. 80, 149–157 (2002).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank G. Waro for genetic crosses and technical assistance. We thank H. Bellen (Baylor College of Medicine) for the antibody to Dα7 and the Dα7-deficient mutant line, S. Sigrist (Institute for Biology/Genetics) for the UAS–nAcRα-18C-EGFP fly line, M. Fujioka (Thomas Jefferson University) for the RRa-GAL4, RN2-GAL4 and EL-GAL4 fly lines, S. Singh (State University of New York, Buffalo) for the Shab[3] line, and E. Gundelfinger and U. Thomas (Leibniz Institute for Neurobiology) for the antibodies to Drosophila nAChRs. We also thank C. Yeung for carrying out genetic mapping and crosses for the transgenic HA-Shal line. S.T. is supported by a grant from the US National Institutes of Health (R01 GM083335).

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Y.P. conducted all of the experiments and analyzed all of the data. S.T. supervised the project and wrote the majority of the manuscript.

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Correspondence to Susan Tsunoda.

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Ping, Y., Tsunoda, S. Inactivity-induced increase in nAChRs upregulates Shal K+ channels to stabilize synaptic potentials. Nat Neurosci 15, 90–97 (2012). https://doi.org/10.1038/nn.2969

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