Parallel processing in two transmitter microenvironments at the cone photoreceptor synapse
Parallel processing in two transmitter microenvironments at the cone photoreceptor synapse
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DOI：
10.1016/j.neuron.2006.04.034
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发表时间：
2006-06-01
期刊：
影响因子：
16.2
通讯作者：
Saszik, Shannon
中科院分区：
文献类型：
--
作者：
DeVries, Steven H.;Li, Wei;Saszik, Shannon
视锥细胞感光器在狭窄的膜内陷顶部的带状物上释放谷氨酸，这些内陷空到末端基底上。锥状终端的独特形状表明，有两个发射机微环境：内陷，浓度高，曝光是短暂的;在基地，浓度低，曝光是平滑的扩散。使用多细胞电压钳记录，我们表明，不同亚型的关闭双极细胞样品发射器在两个微环境。含有AMPA受体的细胞的树突插入内陷并感知谷氨酸浓度的快速波动，这可能导致短暂的反应。含有红藻氨酸受体的细胞的树突进行基底接触，并对产生持续反应的谷氨酸的平滑流动作出反应。在视锥细胞到关闭双极细胞突触的信号传递说明了递质溢出和突触结构如何联合收割机在突触后神经元中产生不同的信号。
A cone photoreceptor releases glutamate at ribbons located atop narrow membrane invaginations that empty onto a terminal base. The unique shape of the cone terminal suggests that there are two transmitter microenvironments: within invaginations, where concentrations are high and exposures are brief; and at the base, where concentrations are low and exposure is smoothed by diffusion. Using multicell voltage-clamp recording, we show that different subtypes of Off bipolar cells sample transmitter in two microenvironments. The dendrites of an AMPA receptor-containing cell insert into invaginations and sense rapid fluctuations in glutamate concentration that can lead to transient responses. The dendrites of kainate receptor-containing cells make basal contacts and respond to a smoothed flow of glutamate that produces sustained responses. Signaling at the cone to Off bipolar cell synapse illustrates how transmitter spillover and synapse architecture can combine to produce distinct signals in postsynaptic neurons.