Kainate Receptors Mediate Signaling in Both Transient and Sustained OFF Bipolar Cell Pathways in Mouse Retina
Kainate Receptors Mediate Signaling in Both Transient and Sustained OFF Bipolar Cell Pathways in Mouse Retina
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DOI：
10.1523/jneurosci.4941-13.2014
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发表时间：
2014-04-30
影响因子：
5.3
通讯作者：
Demb, Jonathan B.
中科院分区：
文献类型：
--
作者：
Borghuis, Bart G.;Looger, Loren L.;Demb, Jonathan B.
感觉神经科学的一个基本问题是如何在分子和电路机制水平上实现并行处理。在视网膜中，已经提出不同的OFF锥双极细胞类型分别通过ampa和kainate型谷氨酸受体的差异表达产生快速/短暂和缓慢/持续的通路。然而，在光刺激下，这些受体在完整回路中的功能意义尚不清楚。在这里，我们通过在突触后无突和神经节细胞树突上表达的谷氨酸传感器（iGluSnFR）的双光子成像来测量小鼠双极细胞的谷氨酸释放。在短暂和持续的OFF层中，双极细胞的锥体驱动的谷氨酸释放被kainate受体拮抗剂阻断，但AMPA受体不被阻断。双极和神经节细胞的电生理记录证实了盐酸盐受体在短暂和持续的OFF通路中信号传导的重要作用。蓝酸盐受体介导的对比度调制高达20赫兹的反应。所有小鼠OFF双极通路的光诱发反应依赖于kainate受体，而不是AMPA受体。
A fundamental question in sensory neuroscience is how parallel processing is implemented at the level of molecular and circuit mechanisms. In the retina, it has been proposed that distinct OFF cone bipolar cell types generate fast/transient and slow/sustained pathways by the differential expression of AMPA-and kainate-type glutamate receptors, respectively. However, the functional significance of these receptors in the intact circuit during light stimulation remains unclear. Here, we measured glutamate release from mouse bipolar cells by two-photon imaging of a glutamate sensor (iGluSnFR) expressed on postsynaptic amacrine and ganglion cell dendrites. In both transient and sustained OFF layers, cone-driven glutamate release from bipolar cells was blocked by antagonists to kainate receptors but not AMPA receptors. Electrophysiological recordings from bipolar and ganglion cells confirmed the essential role of kainate receptors for signaling in both transient and sustained OFF pathways. Kainate receptors mediated responses to contrast modulation up to 20 Hz. Light-evoked responses in all mouse OFF bipolar pathways depend on kainate, not AMPA, receptors.