P2X(7)R modulation of visually evoked synaptic responses in the retina.
P2X(7)R modulation of visually evoked synaptic responses in the retina.
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DOI：
10.1007/s11302-016-9522-7
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发表时间：
2016-12
影响因子：
3.5
通讯作者：
Salt, Thomas E.
中科院分区：
文献类型：
--
作者：
Chavda, Seetal;Luthert, Philip J.;Salt, Thomas E.
P2X7R 分布在视网膜的所有层中，因此，它们在各种细胞类型上的定位使人们对其特定的作用位点产生疑问。本研究使用暗适应的离体小鼠视网膜整体制备，旨在表征在可比条件下 P2X7R 激活对光诱发的兴奋性 RGC ON 场兴奋性突触后电位 (fEPSP) 和外层视网膜视网膜电图 (ERG) 反应的影响。在 BzATP 存在的情况下，药理学分离的 NMDA 受体介导的 RGC ON-fEPSP 减少，这种作用被 A438079 和其他选择性 P2X7R 拮抗剂 A804598 或 AF27139 显着减弱。在生理克雷布斯培养基中，BzATP 诱导 ERG a 波显着增强，同时 b 波和振荡电位的功率降低。相反，在药理学改良的不含 Mg2+ 的灌注液中，BzATP 降低了 a 波和 b 波。 BzATP 对 ERG 成分的影响被 A438079 抑制。生理条件下 P2X7R 功能在内外视网膜视觉处理中的作用仍存在争议。 ON-fEPSP 在 A804598 存在下显着降低，但 A438079 或 AF27139 则没有显着降低。此外，A438079 对生理克雷布斯中的 ERG 成分没有任何影响，但当应用于药理学改良的介质时，A438079 分别增强和减少了 a 波和 b 波。因此，P2X7Rs 的激活会影响视网膜 ON 通路的功能。高浓度细胞外 ATP 的存在很可能有助于病理生理微环境中视网膜视觉传输的调节。
P2X7Rs are distributed throughout all layers of the retina, and thus, their localisation on various cell types puts into question their specific site(s) of action. Using a dark-adapted, ex vivo mouse retinal whole mount preparation, the present study aimed to characterise the effect of P2X7R activation on light-evoked, excitatory RGC ON-field excitatory post-synaptic potentials (fEPSPs) and on outer retinal electroretinogram (ERG) responses under comparable conditions. The pharmacologically isolated NMDA receptor-mediated RGC ON-fEPSP was reduced in the presence of BzATP, an effect which was significantly attenuated by A438079 and other selective P2X7R antagonists A804598 or AF27139. In physiological Krebs medium, BzATP induced a significant potentiation of the ERG a-wave, with a concomitant reduction in the b-wave and the power of the oscillatory potentials. Conversely, in the pharmacologically modified Mg2+-free perfusate, BzATP reduced both the a-wave and b-wave. The effects of BzATP on the ERG components were suppressed by A438079. A role for P2X7R function in visual processing in both the inner and outer retina under physiological conditions remains controversial. The ON-fEPSP was significantly reduced in the presence of A804598 but not by A438079 or AF27139. Furthermore, A438079 did not have any effect on the ERG components in physiological Krebs but potentiated and reduced the a-wave and b-wave, respectively, when applied to the pharmacologically modified medium. Therefore, activation of P2X7Rs affects the function in the retinal ON pathway. The presence of a high concentration of extracellular ATP would most likely contribute to the modulation of visual transmission in the retina in the pathophysiological microenvironment.
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DOI：
10.1523/jneurosci.3295-09.2010
发表时间：
2010-01-13
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Clark AK;Staniland AA;Marchand F;Kaan TK;McMahon SB;Malcangio M
通讯作者：
Malcangio M
影响因子：
5.5
作者：
Bloomfield, SA;Xin, DY
通讯作者：
Xin, DY
影响因子：
2.9
作者：
Kaneda, Makoto;Ito, Koichi;Shimoda, Yukio
通讯作者：
Shimoda, Yukio
影响因子：
1.9
作者：
HOOD, DC;BIRCH, DG
通讯作者：
BIRCH, DG
影响因子：
7.3
作者：
Donnelly-Roberts, Diana L.;Namovic, Marian T.;Jarvis, Michael F.
通讯作者：
Jarvis, Michael F.