Muller J F, Ammermüller J, Normann R A, Kolb H
Department of Physiology, University of Utah School of Medicine, Salt Lake City.
Vis Neurosci. 1991 Nov;7(5):409-29. doi: 10.1017/s0952523800009718.
Two physiologically distinct, HRP-marked turtle retinal ganglion cells were examined for their morphology, GABAergic, glycinergic, and bipolar cell synaptic inputs, using electron-microscopic autoradiography and postembedding immunocytochemistry. One cell was a color-opponent, transient ON/OFF ganglion cell. Its center response to red was a sustained hyperpolarization, and its center response to green was a depolarization with increased spiking at onset. The HRP-injected cell most resembled G6, from previous Golgi-impregnation studies (Kolb, 1982; Kolb et al., 1988). It was a narrow-field bistratified cell, whose two broad dendritic strata peaked at approximately levels L20-25 (sublamina a) and L60 (sublamina b) of the inner plexiform layer. Bipolar cell synapses onto G6 were found evenly distributed between its distal and proximal dendritic strata, spanning L20-75. These inputs probably originated from several different bipolar cells, reflecting the complexity of the center response. GABAergic inputs were found onto both the distal and proximal strata, from near L20-L85. Only a few glycinergic inputs, confined to dendrites at L50-70, were observed. A second ganglion cell type that we physiologically characterized and HRP-injected had sustained ON-center, sustained OFF-surround responses. Two examples were studied; both were bistratified in sublamina b, near L60-70 and L85-100, with branches up to near L40. They resembled G10, from previous Golgi-impregnation studies (Kolb, 1982; Kolb et al., 1988). One cell was partially reconstructed to look at the distributions of GABAergic and glycinergic amacrine cell, and bipolar cell inputs. Although synapses from bipolar cells were equally divided between the two major dendritic strata of G10, the inputs to the distal stratum were close to the soma, and the inputs to the more proximal stratum were on the peripheral dendrites. This arrangement may reflect input from two distinct types of ON-bipolar cell. GABAergic and glycinergic inputs to G10 costratified to both strata and to the distal branches; but where glycinergic inputs were found distributed throughout the arbor, GABAergic inputs appeared to be confined to peripheral dendrites. We hypothesize on the neural elements involved and the circuitry that may underlie the physiologically recorded receptive fields of these two very different ganglion cell types in the turtle retina.
利用电子显微镜放射自显影术和包埋后免疫细胞化学技术，对两种生理特性不同、经辣根过氧化物酶（HRP）标记的龟视网膜神经节细胞进行了形态学、γ-氨基丁酸能（GABAergic）、甘氨酸能和双极细胞突触输入方面的研究。其中一个细胞是颜色拮抗型瞬态开/关神经节细胞。它对红色的中心反应是持续的超极化，对绿色的中心反应是去极化且在开始时放电增加。注入HRP的这个细胞与先前高尔基染色研究（Kolb，1982；Kolb等人，1988）中的G6细胞最为相似。它是一个窄场双分层细胞，其两个宽阔的树突层在大约内网状层的L20 - 25（a亚层）和L60（b亚层）水平达到峰值。双极细胞与G6细胞的突触在其远端和近端树突层之间均匀分布，跨度为L20 - 75。这些输入可能来自几种不同的双极细胞，反映了中心反应的复杂性。在远端和近端层均发现了GABA能输入，范围从L20 - L85附近。仅观察到少数甘氨酸能输入，局限于L50 - 70的树突。我们生理特征化并注入HRP的第二种神经节细胞类型具有持续的开中心、持续的关周边反应。研究了两个例子；两者均在b亚层双分层，靠近L60 - 70和L85 - 100，分支可达L40附近。它们与先前高尔基染色研究（Kolb，1982；Kolb等人，1988）中的G10细胞相似。对其中一个细胞进行了部分重建，以观察GABA能和甘氨酸能无长突细胞以及双极细胞输入的分布。尽管来自双极细胞的突触在G10细胞的两个主要树突层之间平均分配，但远端层的输入靠近胞体，而更近端层的输入位于周边树突上。这种排列可能反映了来自两种不同类型的开双极细胞的输入。G10细胞的GABA能和甘氨酸能输入共分层于两个层和远端分支；但在发现甘氨酸能输入分布于整个树突的地方，GABA能输入似乎局限于周边树突。我们对涉及的神经元成分以及可能构成龟视网膜中这两种非常不同的神经节细胞类型生理记录感受野基础的神经回路进行了推测。
