Abstract
1. We have used non-stationary variance analysis to examine the single channel conductance and the probability of channel opening at the peak of the homomeric GluR6 response (Po,peak) to 100-200 ms application (10-90% exchange time, 0.3 ms) of glutamate onto excised membrane patches from transiently transfected human embryonic kidney cells (HEK 293). 2. Our determinations of both Po,peak and single channel conductance of simulated current responses are insensitive to system filtering, response rise time, desensitization rate and measured variation in our drug perfusion speed. Isolation of stochastic current fluctuations using the local mean response waveform minimizes problems associated with modest rundown of response amplitude during the experiment. 3. The slope conductance calculated from the weighted mean unitary currents for the channels activated in response to glutamate application is 16 pS. Chord conductance between-40 and -80 mV is independent of agonist concentration. Conversion of the codon for glutamine621 to arginine (Q621R) by RNA editing reduces conductance by more than 35-fold to less than 0.4 pS without changing response time course, desensitization, or Po,peak. 4. Po,peak is high at saturating glutamate concentrations (0.65 +/- 0.23; mean +/- S.D.) and varies with agonist concentrations. The half-maximally effective glutamate concentration (EC50) determined for Po,peak (0.2 mM; Hill slope = 0.6) is similar to that determined for the macroscopic peak current amplitude (0.5 mM; Hill slope = 1.0) in response to rapid agonist application. 5. Inclusion of the purified catalytic subunit of cAMP-dependent protein kinase A (PKA) in the patch pipette increases Po,peak to 0.85 +/- 0.12 and co-transfection of cells with a cDNA encoding the catalytic subunit of PKA (C alpha-PKA) increases Po,peak to 0.94 +/- 0.09. 6. Inclusion of purified calcineurin plus its coactivators 200 nM Ca2+ and calmodulin in the patch pipette decreases Po,peak to 0.48 +/- 0.10. The calcineurin-stimulated decrease of Po,peak in cells co-transfected with C alpha-PKA is blocked by 800 nM deltamethrin, a calcineurin inhibitor. Calmodulin, 200 nM Ca2+ and deltamethrin have no effect on Po,peak in the absence of calcineurin. As predicted from its effects on Po,peak, inclusion of calcineurin in the patch pipette accelerates the run-down of whole cell GluR6 responses in cells co-transfected with C alpha-PKA. 7. The effects of both calcineurin and PKA on Po,peak for GluR6 receptors in excised patches occur without any detectable changes to response time course, desensitization, or chord conductance. 8. We conclude that the binding of glutamate to homomeric GluR6 receptors is associated with a high probability of channel opening, which is under the control of two signalling systems that are known to be co-localized at the neuronal membrane: PKA (Po,peak near 1.0) and calcineurin (Po,peak near 0.5).
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- Asztély F., Gustafsson B. Ionotropic glutamate receptors. Their possible role in the expression of hippocampal synaptic plasticity. Mol Neurobiol. 1996 Feb;12(1):1–11. doi: 10.1007/BF02740744. [DOI] [PubMed] [Google Scholar]
- Bowie D., Mayer M. L. Inward rectification of both AMPA and kainate subtype glutamate receptors generated by polyamine-mediated ion channel block. Neuron. 1995 Aug;15(2):453–462. doi: 10.1016/0896-6273(95)90049-7. [DOI] [PubMed] [Google Scholar]
- Bradford H. F. Glutamate, GABA and epilepsy. Prog Neurobiol. 1995 Dec;47(6):477–511. doi: 10.1016/0301-0082(95)00030-5. [DOI] [PubMed] [Google Scholar]
- Burnashev N., Villarroel A., Sakmann B. Dimensions and ion selectivity of recombinant AMPA and kainate receptor channels and their dependence on Q/R site residues. J Physiol. 1996 Oct 1;496(Pt 1):165–173. doi: 10.1113/jphysiol.1996.sp021674. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chen C., Okayama H. High-efficiency transformation of mammalian cells by plasmid DNA. Mol Cell Biol. 1987 Aug;7(8):2745–2752. doi: 10.1128/mcb.7.8.2745. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Choi D. W. Bench to bedside: the glutamate connection. Science. 1992 Oct 9;258(5080):241–243. doi: 10.1126/science.1357748. [DOI] [PubMed] [Google Scholar]
- Coghlan V. M., Perrino B. A., Howard M., Langeberg L. K., Hicks J. B., Gallatin W. M., Scott J. D. Association of protein kinase A and protein phosphatase 2B with a common anchoring protein. Science. 1995 Jan 6;267(5194):108–111. doi: 10.1126/science.7528941. [DOI] [PubMed] [Google Scholar]
- Colquhoun D., Hawkes A. G. Relaxation and fluctuations of membrane currents that flow through drug-operated channels. Proc R Soc Lond B Biol Sci. 1977 Nov 14;199(1135):231–262. doi: 10.1098/rspb.1977.0137. [DOI] [PubMed] [Google Scholar]
- Colquhoun D., Ogden D. C. Activation of ion channels in the frog end-plate by high concentrations of acetylcholine. J Physiol. 1988 Jan;395:131–159. doi: 10.1113/jphysiol.1988.sp016912. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cull-Candy S. G., Howe J. R., Ogden D. C. Noise and single channels activated by excitatory amino acids in rat cerebellar granule neurones. J Physiol. 1988 Jun;400:189–222. doi: 10.1113/jphysiol.1988.sp017117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- De Koninck Y., Mody I. Noise analysis of miniature IPSCs in adult rat brain slices: properties and modulation of synaptic GABAA receptor channels. J Neurophysiol. 1994 Apr;71(4):1318–1335. doi: 10.1152/jn.1994.71.4.1318. [DOI] [PubMed] [Google Scholar]
- Douglass J. K., Wilkens L., Pantazelou E., Moss F. Noise enhancement of information transfer in crayfish mechanoreceptors by stochastic resonance. Nature. 1993 Sep 23;365(6444):337–340. doi: 10.1038/365337a0. [DOI] [PubMed] [Google Scholar]
- Edmonds B., Colquhoun D. Rapid decay of averaged single-channel NMDA receptor activations recorded at low agonist concentration. Proc Biol Sci. 1992 Dec 22;250(1329):279–286. doi: 10.1098/rspb.1992.0160. [DOI] [PubMed] [Google Scholar]
- Egebjerg J., Heinemann S. F. Ca2+ permeability of unedited and edited versions of the kainate selective glutamate receptor GluR6. Proc Natl Acad Sci U S A. 1993 Jan 15;90(2):755–759. doi: 10.1073/pnas.90.2.755. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ehlers M. D., Zhang S., Bernhadt J. P., Huganir R. L. Inactivation of NMDA receptors by direct interaction of calmodulin with the NR1 subunit. Cell. 1996 Mar 8;84(5):745–755. doi: 10.1016/s0092-8674(00)81052-1. [DOI] [PubMed] [Google Scholar]
- Enan E., Matsumura F. Specific inhibition of calcineurin by type II synthetic pyrethroid insecticides. Biochem Pharmacol. 1992 Apr 15;43(8):1777–1784. doi: 10.1016/0006-2952(92)90710-z. [DOI] [PubMed] [Google Scholar]
- Gibb A. J., Colquhoun D. Activation of N-methyl-D-aspartate receptors by L-glutamate in cells dissociated from adult rat hippocampus. J Physiol. 1992 Oct;456:143–179. doi: 10.1113/jphysiol.1992.sp019331. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gibb A. J., Kojima H., Carr J. A., Colquhoun D. Expression of cloned receptor subunits produces multiple receptors. Proc Biol Sci. 1990 Nov 22;242(1304):108–112. doi: 10.1098/rspb.1990.0112. [DOI] [PubMed] [Google Scholar]
- Greene J. G., Greenamyre J. T. Bioenergetics and glutamate excitotoxicity. Prog Neurobiol. 1996 Apr;48(6):613–634. doi: 10.1016/0301-0082(96)00006-8. [DOI] [PubMed] [Google Scholar]
- Greengard P., Jen J., Nairn A. C., Stevens C. F. Enhancement of the glutamate response by cAMP-dependent protein kinase in hippocampal neurons. Science. 1991 Sep 6;253(5024):1135–1138. doi: 10.1126/science.1716001. [DOI] [PubMed] [Google Scholar]
- Heckmann M., Bufler J., Franke C., Dudel J. Kinetics of homomeric GluR6 glutamate receptor channels. Biophys J. 1996 Oct;71(4):1743–1750. doi: 10.1016/S0006-3495(96)79375-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heinemann S. H., Conti F. Nonstationary noise analysis and application to patch clamp recordings. Methods Enzymol. 1992;207:131–148. doi: 10.1016/0076-6879(92)07009-d. [DOI] [PubMed] [Google Scholar]
- Hestrin S. Activation and desensitization of glutamate-activated channels mediating fast excitatory synaptic currents in the visual cortex. Neuron. 1992 Nov;9(5):991–999. doi: 10.1016/0896-6273(92)90250-h. [DOI] [PubMed] [Google Scholar]
- Hollmann M., Heinemann S. Cloned glutamate receptors. Annu Rev Neurosci. 1994;17:31–108. doi: 10.1146/annurev.ne.17.030194.000335. [DOI] [PubMed] [Google Scholar]
- Howe J. R. Homomeric and heteromeric ion channels formed from the kainate-type subunits GluR6 and KA2 have very small, but different, unitary conductances. J Neurophysiol. 1996 Jul;76(1):510–519. doi: 10.1152/jn.1996.76.1.510. [DOI] [PubMed] [Google Scholar]
- Huettner J. E. Glutamate receptor channels in rat DRG neurons: activation by kainate and quisqualate and blockade of desensitization by Con A. Neuron. 1990 Sep;5(3):255–266. doi: 10.1016/0896-6273(90)90163-a. [DOI] [PubMed] [Google Scholar]
- Huganir R. L., Greengard P. Regulation of neurotransmitter receptor desensitization by protein phosphorylation. Neuron. 1990 Nov;5(5):555–567. doi: 10.1016/0896-6273(90)90211-w. [DOI] [PubMed] [Google Scholar]
- Jahr C. E. High probability opening of NMDA receptor channels by L-glutamate. Science. 1992 Jan 24;255(5043):470–472. doi: 10.1126/science.1346477. [DOI] [PubMed] [Google Scholar]
- Knapp A. G., Schmidt K. F., Dowling J. E. Dopamine modulates the kinetics of ion channels gated by excitatory amino acids in retinal horizontal cells. Proc Natl Acad Sci U S A. 1990 Jan;87(2):767–771. doi: 10.1073/pnas.87.2.767. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kullmann D. M., Siegelbaum S. A. The site of expression of NMDA receptor-dependent LTP: new fuel for an old fire. Neuron. 1995 Nov;15(5):997–1002. doi: 10.1016/0896-6273(95)90089-6. [DOI] [PubMed] [Google Scholar]
- Köhler M., Burnashev N., Sakmann B., Seeburg P. H. Determinants of Ca2+ permeability in both TM1 and TM2 of high affinity kainate receptor channels: diversity by RNA editing. Neuron. 1993 Mar;10(3):491–500. doi: 10.1016/0896-6273(93)90336-p. [DOI] [PubMed] [Google Scholar]
- Lieberman D. N., Mody I. Regulation of NMDA channel function by endogenous Ca(2+)-dependent phosphatase. Nature. 1994 May 19;369(6477):235–239. doi: 10.1038/369235a0. [DOI] [PubMed] [Google Scholar]
- Neher E., Stevens C. F. Conductance fluctuations and ionic pores in membranes. Annu Rev Biophys Bioeng. 1977;6:345–381. doi: 10.1146/annurev.bb.06.060177.002021. [DOI] [PubMed] [Google Scholar]
- Newland C. F., Colquhoun D., Cull-Candy S. G. Single channels activated by high concentrations of GABA in superior cervical ganglion neurones of the rat. J Physiol. 1991 Jan;432:203–233. doi: 10.1113/jphysiol.1991.sp018382. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peng Y. W., Blackstone C. D., Huganir R. L., Yau K. W. Distribution of glutamate receptor subtypes in the vertebrate retina. Neuroscience. 1995 May;66(2):483–497. doi: 10.1016/0306-4522(94)00569-q. [DOI] [PubMed] [Google Scholar]
- Raman I. M., Trussell L. O. Concentration-jump analysis of voltage-dependent conductances activated by glutamate and kainate in neurons of the avian cochlear nucleus. Biophys J. 1995 Nov;69(5):1868–1879. doi: 10.1016/S0006-3495(95)80057-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raymond L. A., Blackstone C. D., Huganir R. L. Phosphorylation and modulation of recombinant GluR6 glutamate receptors by cAMP-dependent protein kinase. Nature. 1993 Feb 18;361(6413):637–641. doi: 10.1038/361637a0. [DOI] [PubMed] [Google Scholar]
- Roberson E. D., Sweatt J. D. Transient activation of cyclic AMP-dependent protein kinase during hippocampal long-term potentiation. J Biol Chem. 1996 Nov 29;271(48):30436–30441. doi: 10.1074/jbc.271.48.30436. [DOI] [PubMed] [Google Scholar]
- Robinson H. P., Sahara Y., Kawai N. Nonstationary fluctuation analysis and direct resolution of single channel currents at postsynaptic sites. Biophys J. 1991 Feb;59(2):295–304. doi: 10.1016/S0006-3495(91)82223-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roche K. W., O'Brien R. J., Mammen A. L., Bernhardt J., Huganir R. L. Characterization of multiple phosphorylation sites on the AMPA receptor GluR1 subunit. Neuron. 1996 Jun;16(6):1179–1188. doi: 10.1016/s0896-6273(00)80144-0. [DOI] [PubMed] [Google Scholar]
- Roche K. W., Tingley W. G., Huganir R. L. Glutamate receptor phosphorylation and synaptic plasticity. Curr Opin Neurobiol. 1994 Jun;4(3):383–388. doi: 10.1016/0959-4388(94)90100-7. [DOI] [PubMed] [Google Scholar]
- Rosenmund C., Carr D. W., Bergeson S. E., Nilaver G., Scott J. D., Westbrook G. L. Anchoring of protein kinase A is required for modulation of AMPA/kainate receptors on hippocampal neurons. Nature. 1994 Apr 28;368(6474):853–856. doi: 10.1038/368853a0. [DOI] [PubMed] [Google Scholar]
- Rosenmund C., Feltz A., Westbrook G. L. Synaptic NMDA receptor channels have a low open probability. J Neurosci. 1995 Apr;15(4):2788–2795. doi: 10.1523/JNEUROSCI.15-04-02788.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ruano D., Lambolez B., Rossier J., Paternain A. V., Lerma J. Kainate receptor subunits expressed in single cultured hippocampal neurons: molecular and functional variants by RNA editing. Neuron. 1995 May;14(5):1009–1017. doi: 10.1016/0896-6273(95)90339-9. [DOI] [PubMed] [Google Scholar]
- Scheetz A. J., Constantine-Paton M. Modulation of NMDA receptor function: implications for vertebrate neural development. FASEB J. 1994 Jul;8(10):745–752. doi: 10.1096/fasebj.8.10.8050674. [DOI] [PubMed] [Google Scholar]
- Sigworth F. J. The variance of sodium current fluctuations at the node of Ranvier. J Physiol. 1980 Oct;307:97–129. doi: 10.1113/jphysiol.1980.sp013426. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silberberg S. D., Magleby K. L. Preventing errors when estimating single channel properties from the analysis of current fluctuations. Biophys J. 1993 Oct;65(4):1570–1584. doi: 10.1016/S0006-3495(93)81196-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silver R. A., Cull-Candy S. G., Takahashi T. Non-NMDA glutamate receptor occupancy and open probability at a rat cerebellar synapse with single and multiple release sites. J Physiol. 1996 Jul 1;494(Pt 1):231–250. doi: 10.1113/jphysiol.1996.sp021487. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Soderling T. R., Tan S. E., McGlade-McCulloh E., Yamamoto H., Fukunaga K. Excitatory interactions between glutamate receptors and protein kinases. J Neurobiol. 1994 Mar;25(3):304–311. doi: 10.1002/neu.480250310. [DOI] [PubMed] [Google Scholar]
- Spruston N., Jonas P., Sakmann B. Dendritic glutamate receptor channels in rat hippocampal CA3 and CA1 pyramidal neurons. J Physiol. 1995 Jan 15;482(Pt 2):325–352. doi: 10.1113/jphysiol.1995.sp020521. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sutcliffe M. J., Wo Z. G., Oswald R. E. Three-dimensional models of non-NMDA glutamate receptors. Biophys J. 1996 Apr;70(4):1575–1589. doi: 10.1016/S0006-3495(96)79724-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Swanson G. T., Feldmeyer D., Kaneda M., Cull-Candy S. G. Effect of RNA editing and subunit co-assembly single-channel properties of recombinant kainate receptors. J Physiol. 1996 Apr 1;492(Pt 1):129–142. doi: 10.1113/jphysiol.1996.sp021295. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Traynelis S. F., Silver R. A., Cull-Candy S. G. Estimated conductance of glutamate receptor channels activated during EPSCs at the cerebellar mossy fiber-granule cell synapse. Neuron. 1993 Aug;11(2):279–289. doi: 10.1016/0896-6273(93)90184-s. [DOI] [PubMed] [Google Scholar]
- Wang J. H., Stelzer A. Inhibition of phosphatase 2B prevents expression of hippocampal long-term potentiation. Neuroreport. 1994 Nov 21;5(17):2377–2380. doi: 10.1097/00001756-199411000-00041. [DOI] [PubMed] [Google Scholar]
- Wang L. Y., Salter M. W., MacDonald J. F. Regulation of kainate receptors by cAMP-dependent protein kinase and phosphatases. Science. 1991 Sep 6;253(5024):1132–1135. doi: 10.1126/science.1653455. [DOI] [PubMed] [Google Scholar]
- Wang L. Y., Taverna F. A., Huang X. P., MacDonald J. F., Hampson D. R. Phosphorylation and modulation of a kainate receptor (GluR6) by cAMP-dependent protein kinase. Science. 1993 Feb 19;259(5098):1173–1175. doi: 10.1126/science.8382377. [DOI] [PubMed] [Google Scholar]
- Whetsell W. O., Jr Current concepts of excitotoxicity. J Neuropathol Exp Neurol. 1996 Jan;55(1):1–13. doi: 10.1097/00005072-199601000-00001. [DOI] [PubMed] [Google Scholar]
- Wiesenfeld K., Moss F. Stochastic resonance and the benefits of noise: from ice ages to crayfish and SQUIDs. Nature. 1995 Jan 5;373(6509):33–36. doi: 10.1038/373033a0. [DOI] [PubMed] [Google Scholar]
- Wisden W., Seeburg P. H. A complex mosaic of high-affinity kainate receptors in rat brain. J Neurosci. 1993 Aug;13(8):3582–3598. doi: 10.1523/JNEUROSCI.13-08-03582.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wyllie D. J., Traynelis S. F., Cull-Candy S. G. Evidence for more than one type of non-NMDA receptor in outside-out patches from cerebellar granule cells of the rat. J Physiol. 1993 Apr;463:193–226. doi: 10.1113/jphysiol.1993.sp019591. [DOI] [PMC free article] [PubMed] [Google Scholar]