Cone bipolar cells as interneurons in the rod pathway of the rabbit retina.
Cone bipolar cells as interneurons in the rod pathway of the rabbit retina.
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视锥双极细胞作为兔视网膜视杆通路中的中间神经元。
DOI：
10.1002/cne.903470111
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Raviola,E
中科院分区：
文献类型：
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作者：
Strettoi,E;Dacheux,RF;Raviola,E
在哺乳动物视网膜中，视杆信号通过视杆双极传递到窄视野双层（AII）无长突细胞。这个神经元，反过来，使间隙连接与轴突树枝状锥双极细胞，驻留在玻璃体的一半（sublaminab）的内丛状层（IPL）。在检查了兔子视网膜中的杆双极和AII无长突后，我们现在已经从连续系列薄切片的电子显微照片重建了锥体双极细胞轴突分支的突触连接，这些轴突分支与AII无长突的缝隙连接数量最多。这些轴突分支狭窄地局限于第4层（S4）。并使带状突触与属于神经节或无长突细胞的突触后树突的二分体形成。在突触后突起的人口，30%的神经节细胞树突。这些树突可能至少部分起源于单中心神经节细胞，因为它们的行程仅限于IPL的板下层。其余的突触后突起中，51.7%属于无长突细胞，18.3%未被识别。在突触后无长突细胞突起中，有33.3%的突触返回到锥体双极末梢上。这些相互突触的轴突arborizations上的总输入的21.3%，其余部分（78.7%）所产生的一个异质性的无长突树突，是纯粹的突触前锥双极末梢的人口。突触前和突触后无长突是几个不同微电路的一部分，这表明杆和锥信号的复杂局部处理。因此，在兔IPL的板层下，与AII无长突形成间隙连接的锥双极细胞表现出大量输出到神经节细胞。这一事实，结合我们先前的观察，即在这个亚板层神经节细胞中，从视杆双极和AII无长突接收的输入可以忽略不计，表明在兔中，视锥双极代表视杆信号到消化道中心神经节细胞的途径中的必要联系。因此，视杆细胞和视锥细胞的信号最终共享相同的整合机制，并汇聚到同一组神经节细胞上。© 1994 Wiley利斯公司
In the mammalian retina, rod signals are transmitted by rod bipolars to the narrow‐field, bistratified (AII) amacrine cell. This neuron, in turn, makes gap junctions with the axonal arborization of cone bipolar cells that reside in the vitreal half (sublaminab) of the inner plexiform layer (IPL). After examining rod bipolars and AII amacrines in the rabbit retina, we have now reconstructed from electron micrographs of continuous series of thin sections the synaptic connections of the axonal arborizations of cone bipolar cells that make the highest number of gap junctions with AII amacrines.These axonal arborizations were narrowly confined to stratum 4 (S4) of the IPL and made ribbon synapses to dyads of postsynaptic‐dendrites that belonged to either ganglion or amacrine cells. In the population of postsynaptic processes, 30% were ganglion cell dendrites. These dendrites were probably originating, at least in part, fromon‐center ganglion cells because their course was confined to sublaminabof the IPL. Of the remaining postsynaptic processes, 51.7% belonged to amacrine cells and 18.3% were not identified. Among the postsynaptic amacrine cell processes, 33.3% returned a reciprocal synapse onto the cone bipolar endings. These reciprocal synapses represented 21.3% of the total input onto the axonal arborizations, the remaining fraction (78.7%) arising from a heterogeneous population of amacrine dendrites that were purely presynaptic to the cone bipolars endings. Pre‐ and postsynaptic amacrines were part of several distinct microcircuits which suggest complex local processing of both rod and cone signals.Thus, the cone bipolars that make gap junctions with AII amacrines in sublaminabof the rabbit IPL exhibit a substantial output onto ganglion cells. This fact, in conjunction with our previous observations that in this sublamina ganglion cells receive negligible input from rod bipolars and AII amacrines, demonstrates that in the rabbit cone bipolars represent a necessary link in the pathway followed by rod signals to enteron‐center ganglion cells. Thus, rod and cone signals ultimately share the same integrating mechanisms and converge onto the same set of ganglion cells. © 1994 Wiley‐Liss, Inc.