Anatomical investigation on the visual input to the regions related to the optokinetic responses.

NOT和AON都接受视网膜直接输入，对光动力学反应（OKR）起调节作用。膝下纹状体通路影响这种调节，显然是通过参与运动处理的外皮层区域。采用WGA-HRP作为顺行示踪剂，结合GABA免疫组化技术，对猫视网膜和视网膜外侧影上视皮层对NOT和AON的传入神经进行了超微结构研究。视网膜终端（RTs）在非视网膜性视网膜病变和非视网膜性视网膜病变中都是大量存在的。这些末端包含苍白的线粒体和圆形的突触囊泡。NOT中的RTs通常较大，与gaba阴性的常规树突和参与肾小球的含囊泡的gaba阳性树突进行不对称的突触接触，而AON中的RTs较小，主要与常规树突进行不对称接触。AON未见典型的视网膜肾小球。在脑皮层的形态学和突触组织方面，未见与AON有明显差异。ct总是很小，并且与gaba阴性的常规树突不对称接触。本研究结果表明，RTs和ct在突触结构上存在形态学差异，反映了它们在处理视觉信息方面的质的差异。此外，rt在NOT和AON中的形态相同，反映了它们在视觉加工中的独特作用。然后，我们使用示踪剂（小麦胚芽凝集素结合的辣根过氧化物酶，WGA-HRP和霍乱毒素B亚基，CTB）检查了大鼠视网膜和视觉皮层区域（17,18a和18b区域）到NOT的投影，以阐明这两种不同的功能输入是如何组织到OKR的。玻璃体注射CTB几乎只在对侧非晶状体出现顺行标记。在超微结构上，视网膜轴突终末尺寸较小（直径可达0.7 μm），含有圆形突触囊泡和苍白的线粒体，与gaba阳性和gaba阴性的NOT神经元均有不对称的突触接触。视觉皮层17区、17区与18a区、17区与18b区之间的过渡区轴突向同侧非脑区投射。在超微结构上，皮质轴突终末尺寸较小（直径可达0.5 μm），含有圆形突触囊泡，仅与gaba -阴性NOT神经元发生不对称突触接触。通过光镜和电子显微镜观察，皮质-NOT和视网膜-NOT投射模式有相当大的重叠：gaba阴性（可能是非投射）神经元同时接收来自皮质和视网膜终端的输入。从这些结果来看，我们似乎可以合理地假设，来自着色大鼠视觉皮质区的输入与来自视网膜的输入共同控制OKR。少

The NOT and AON, which both receive direct retinal inputs, perform a regulatory function on optokinetic responses (OKR). The geniculostriate pathway influences on this regulation, apparently via extrastriate areas involved in motion processing.Retina and extrastriate lateral suprasylvian visual cortical efferents to NOT and AON have been studied ultrastructually in cats using WGA-HRP as anterograde tracer in combination with GABA immunohistochemistry. Retinal terminals (RTs) are numerous in both NOT and AON. These terminals contain pale mitochondria and round synaptic vesicles. RTs in NOT are often large and make asymmetrical synaptic contact with GABA-negative conventional dendrites and vesicle-containing GABA-positive dendrites which participate in glomeruli, while RTs in AON are small and make asymmetrical contacts mainly with conventional dendrites. No typical retinal glomeruli are found in AON. There appear to be no differences in morphology or synaptic organization of the cortica … More l terminals (CTs) between NOT and AON. CTs always are small, and make asymmetrical contact with GABA-negative conventional dendrites. The present results indicate that RTs and CTs differ morphologically in synaptic structure, reflecting their qualitative difference in processing visual information. Furthermore, RTs are morphologically identical in NOT and AON, reflecting their unique role in visual processing.Then, we have examined the projections from the retina and visual cortical areas (areas 17, 18a and 18b) to NOT in rats using tracers (wheat germ agglutinin-conjugated horseradish peroxidase, WGA-HRP and cholera toxin B subunit, CTB) in order to clarify how these two different functional inputs to OKR are organized. CTB injection into the vitreous body resulted in anterograde label almost exclusively in the contralateral NOT. Ultrastructually, the size of the retinal axon terminals was small (up to 0.7 μm in diameter), contained round synaptic vesicles and pale mitochondria, and made asymmetrical synaptic contacts with both GABA-positive and GABA-negative NOT neurons. Visual cortical area 17 and the transitional area between area 17 and 18a, or between area 17 and 18b projected their axons to the ipsilateral NOT. Ultrastructually, the size of the cortical axon terminals was small (up to 0.5 μm in diameter), contained round synaptic vesicles, and made asymmetrical synaptic contacts only with GABA-negative NOT neurons. With light and electron microscopical observation, there was a considerable overlap in the cortico-NOT and retino-NOT projection pattern : GABA-negative (presumably NOT projection) neurons simultaneously receive input from both cortical and retinal terminals. From these results, it seems reasonable to postulate that inputs from visual cortical areas in the pigmented rat cooperate with those from the retina in controlling OKR. Less