Journal: Journal of Neuroscience

Article Title: Adenosine-Evoked Hyperpolarization of Retinal Ganglion Cells Is Mediated by G-Protein-Coupled Inwardly Rectifying K+ and Small Conductance Ca2+-Activated K+ Channel Activation

doi: 10.1523/jneurosci.2836-09.2009

Figure Lengend Snippet: Figure 1. Hyperpolarization of retinal ganglion cells by the adenosine receptor agonist NECA is mediated by activation of A1 receptors.A,FocalejectionofNECAontoaganglioncellevokesaprolongedhyperpolarization(recordedincurrentclamp)andan outward current (recorded in voltage clamp). B, ON, ON-OFF, and OFF classes of retinal ganglion cells all exhibit NECA-evoked hyperpolarization. Mean response amplitudes (horizontal lines) do not differ between ganglion cell classes. C, There is no corre- lation between the input resistance of retinal ganglion cells and the amplitude of NECA-evoked current. D, E, Antagonists to A2A (ZM 241385), A2B (MRS 1706), and A3 (MRS 1191) receptors have no effect on the NECA-evoked hyperpolarization recorded from ganglioncells,buttheA1antagonistDPCPXdecreasestheNECA-evokedresponseto22%ofcontrol.Antagonistswereappliedsequen- tiallyfor15mineach,withDPCPXappliedlast.Thecurrent-clamptracesinDwereallrecordedfromthesameganglioncell.*p0.001.

Article Snippet: All reagents were purchased from Sigma, except NECA, ZM 241385, MRS 1706, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), and 2-aminoethoxydiphenyl borate (2-APB), which were purchased from Tocris Bioscience; rTertiapin-Q, which was purchased from Alomone Labs; Fluo-4 K salt, which was purchased from Invitrogen; and collagenase and hyaluronidase, which were purchased from Worthington Biochemicals. preliminary experiments, when 5 mM EGTA was included in the intracellular pipette solution, 20% of the ganglion cells tested failed to respond to NECA ejection.

Techniques: Activation Assay

Journal: Journal of Neuroscience

Article Title: Adenosine-Evoked Hyperpolarization of Retinal Ganglion Cells Is Mediated by G-Protein-Coupled Inwardly Rectifying K+ and Small Conductance Ca2+-Activated K+ Channel Activation

doi: 10.1523/jneurosci.2836-09.2009

Figure Lengend Snippet: Figure 7. A component of the NECA-evoked response is generated by SK channels activated by Ca 2 release from internal stores.A,BathapplicationofCPApartiallyreducestheNECA-evokedcurrent.B,RemovalofCa 2fromthebathsolutiondoesnot reducetheNECA-evokedcurrent.TheadditionofapamintotheCa 2-freesolutionpartiallyreducesthecurrent.C,Bathapplica- tionof2-APB,anIP3Rantagonist,partiallyblockstheNECA-evokedcurrent.Theadditionofapamintothe2-APBsolutiondoesnot reducethecurrentfurther.D,Summaryoftheresults.Heparin,asecondIP3Rantagonist,reducestheNECA-evokedresponsetoa similar degree as 2-APB. *p 0.005.

Article Snippet: All reagents were purchased from Sigma, except NECA, ZM 241385, MRS 1706, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), and 2-aminoethoxydiphenyl borate (2-APB), which were purchased from Tocris Bioscience; rTertiapin-Q, which was purchased from Alomone Labs; Fluo-4 K salt, which was purchased from Invitrogen; and collagenase and hyaluronidase, which were purchased from Worthington Biochemicals. preliminary experiments, when 5 mM EGTA was included in the intracellular pipette solution, 20% of the ganglion cells tested failed to respond to NECA ejection.

Techniques: Generated

Journal: Journal of Neuroscience

Article Title: Adenosine-Evoked Hyperpolarization of Retinal Ganglion Cells Is Mediated by G-Protein-Coupled Inwardly Rectifying K+ and Small Conductance Ca2+-Activated K+ Channel Activation

doi: 10.1523/jneurosci.2836-09.2009

Figure Lengend Snippet: Figure8. AdenosinereceptoractivationevokesanIP3R-mediatedintracellularCa2increaseinretinalganglioncells.A,NECA-evoked intracellularCa2changesweremonitoredinthesomaanddendriteofaganglioncellfilledwiththeCa2indicatordyeFluo-4.Calcium traces,showninBandC,weretakenfromregionsdelineatedintheimage.Scalebar,20m.B,NECAevokesasomaticCa2increasethat hasasimilartimecourseastheevokedcurrent.C,NECAevokestransientCa2increasesinadendriteofthesamecell.D,TheNECA-evoked increaseinCa2withinthesomaofaganglioncellisblockedby2-APB.2APBalsoreducestheNECA-evokedoutwardcurrent.E,Summary ofexperimentsshowninD.ThelefttwobarsindicateNECA-evokedCa2responsesincontroland2-APB-treatedretinas.Therightbar showsthe2-APB-mediatedreductioninNECA-evokedcurrent.*p0.001.

Article Snippet: All reagents were purchased from Sigma, except NECA, ZM 241385, MRS 1706, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), and 2-aminoethoxydiphenyl borate (2-APB), which were purchased from Tocris Bioscience; rTertiapin-Q, which was purchased from Alomone Labs; Fluo-4 K salt, which was purchased from Invitrogen; and collagenase and hyaluronidase, which were purchased from Worthington Biochemicals. preliminary experiments, when 5 mM EGTA was included in the intracellular pipette solution, 20% of the ganglion cells tested failed to respond to NECA ejection.

Techniques: