AN ANALYSIS OF TRANSMISSION FROM CONES TO HYPERPOLARIZING BIPOLAR CELLS IN THE RETINA OF THE TURTLE
AN ANALYSIS OF TRANSMISSION FROM CONES TO HYPERPOLARIZING BIPOLAR CELLS IN THE RETINA OF THE TURTLE
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DOI：
10.1113/jphysiol.1983.sp014781
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发表时间：
1983-01-01
影响因子：
5.5
通讯作者：
COPENHAGEN, DR
中科院分区：
文献类型：
--
作者：
ASHMORE, JF;COPENHAGEN, DR
从鳄龟视网膜的中心超偏振双极细胞中记录电压噪声。细胞内染色证实了细胞的身份。在黑暗中存在的膜电位电压波动的方差被100 .mu抑制了高达30倍。M直径的光斑刺激集中在细胞的感受野。当光使光感受器发生超极化并降低从终端释放发射机的速率时，这种降噪是预期的。将波动的光谱作为2个分量的和进行分析：一个分量的功率带宽限制在.apprx以下；10hz，以及形式为Sh(f) = Sh(0)/(1 + (f/f0)2)2的分量Sh(f)，其中f0 = 27hz。这两种成分的产生是由于视锥细胞产生的噪声通过突触传递到双极细胞，以及传递器在双极细胞膜上的作用。递质作用于双极细胞的分量Sh(f)对应于一个事件。持续时间为14毫秒。该事件的峰值幅度在17.6 ~ 223亩之间。平均为69.5 μ V。在黑暗中，造成噪音的这类事件的数量约为。9200 / s。锥体控制中的每个基本噪声事件。30个与递质相关的事件发生在突触上。用匹配滤波的方法分析了稳定照明条件下对黑暗闪光的响应。这些响应在振幅上有波动，对这种波动的分析表明，这是一个与噪声分析中发现的振幅大致相同的基本事件。将刺激点直径扩大到1500亩。M使双极电池重极化，电压噪声随之增加。讨论了中心-环绕组织的突触机制。
Voltage noise was recorded from center-hyperpolarizing bipolar cells in the retina of the snapping turtle. The identity of the cells was confirmed by intracellular staining. The variance of the voltage fluctuations of the membrane potential present in the dark was suppressed by up to 30-fold by 100 .mu.m diameter light spot stimuli centered on the cell''s receptive field. Such noise reduction is expected when light hyperpolarizes the photoreceptors and reduces the rate of release of transmitter from the terminals. The spectra of the fluctuations were analyzed as the sum of 2 components: a component with power band width limited to below .apprx. 10 Hz, and a component Sh(f) of the form Sh(f) = Sh(0)/(1 + (f/f0)2)2, with f0 = 27 Hz. The 2 components were attributed to the noise generated in the cones and transmitted through the synapse to the bipolar cells, and to the action of transmitter on the bipolar cell membrane. The component Sh(f) attributed to the action of transmitter on the bipolar cells corresponded to an event .apprx. 14 ms in duration. The event had a peak amplitude in the range 17.6-223 .mu.V with a mean of 69.5 .mu.V. In the dark, the number of such events contributing to the noise is .apprx. 9200/s. Each elementary noise event in the cones control .apprx. 30 of the transmitter-related events at the synapse. Responses to flashes of darkness applied on steady illumination were analyzed by a method of matched filtering. The responses fluctuated in amplitude, and the analysis of this fluctuation suggested an elementary event of approximately the same amplitude as found from the noise analysis. Enlarging the diameter of the stimulus spot to 1500 .mu.m repolarized the bipolar cells with an associated increase in voltage noise. Implications for the synaptic mechanisms of the center-surround organization were discussed.