FIBER SYSTEMS IN THE OLFACTORY-BULB AND CORTEX - A STUDY IN ADULT AND DEVELOPING RATS, USING THE TIMM METHOD WITH THE LIGHT AND ELECTRON-MICROSCOPE
FIBER SYSTEMS IN THE OLFACTORY-BULB AND CORTEX - A STUDY IN ADULT AND DEVELOPING RATS, USING THE TIMM METHOD WITH THE LIGHT AND ELECTRON-MICROSCOPE
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DOI：
10.1002/cne.902230108
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发表时间：
1984-01-01
影响因子：
2.5
通讯作者：
PRICE, JL
中科院分区：
文献类型：
--
作者：
FRIEDMAN, B;PRICE, JL
用Timm法对大鼠嗅球和皮层的结构进行了描述，其中内源性过渡金属或重金属用硫化物沉淀，然后用Ag染色。在光镜下，在成人前脑的神经元中发现两种类型的染色，一种是精细的着色反应，一种是粗糙的颗粒反应;神经元胞体、纤维束和神经元的某些特定区域几乎不染色。使用EM，Timm方法由与轴突末端相关的小Ag颗粒组成。这些颗粒位于突触前膜的外表面，面向突触间隙和突触囊泡，特别是囊泡膜的内表面。反应性金属与突触递质分泌期间再循环的膜组分有关。在光学显微镜下观察到的着色和颗粒状反应似乎与不同类型轴突终末的不同染色强度相关。嗅觉皮层的全部范围可以由I层的双层染色模式来描绘，这与轴突追踪实验所证明的纤维系统到皮层的终止模式相一致。I层的上部染色非常浅;这正好对应于Ia层，即嗅球纤维的终止区。这一层的深部被强烈的有色反应染色;这正好对应于Ib层，即嗅觉皮层内主要联合纤维系统的终止区。一个突出的颗粒反应，这并不对应于任何已知的长轴突系统，被发现在皮层的所有层，虽然它是集中在表面边缘的第Ib层和第II层。在染色的几个细分的嗅觉皮层的变化进行了说明和描述。在嗅球中，最显著的染色是肾小球结构中相对精细的颗粒状反应，其显然对应于嗅神经末梢。在未成年大鼠中，Timm方法染色整个嗅觉系统的神经元，尽管染色的模式和质量与成年大鼠不同。出生前，最好的分化反应见于嗅球的肾小球，并与嗅神经向内生长的模式密切相关。最早和最突出的反应是在球的尾背部分的改性肾小球复合体中发现的。在嗅觉皮层中，最早的染色发生在出生前的后梨状皮层。皮质染色是不广泛的，直到出生后第1周，和Calleja岛的嗅结节缺乏一个明显的阳性反应，直到出生后第7天。在出生后第3周，嗅皮质的所有部分的染色模式变得类似成人。
The structure of the olfactory bulb and cortex of rats is described using the Timm method, in which endogenous transition or heavy metals are precipitated with sulfide and then stained with Ag. With the light microscope, 2 types of staining, a fine, colored reaction and a coarse, granular reaction, are found in the neuropil of the adult forebrain; neuronal somata, fiber tracts and some specific areas of the neuropil are almost unstained. With the EM the Timm method consists of small Ag granules, which are associated with axon terminals. These granules are located over the external surface of the presynaptic membrane, facing the synpatic cleft and over synaptic vesicles, especially the internal surface of the vesicle membrane. The reactive metals are related to a membrane component which is recycled during secretion of synaptic transmitters. The colored and granular reactions seen with the light microscope appear to be correlated with different intensities of staining of different types of axon terminals. The full extent of the olfactory cortex can be delineated by a bilaminar staining patttern in layer I, which coincides with the pattern of termination of fiber systems to the cortex demonstrated by axonal tracing experiments. The superificial part of layer I is very palely stained; this corresponds precisely to layer Ia, the zone of termination of fibers from the olfactory bulb. The deep part of the layer is stained with an intense colored reaction; this corresponds precisely to layer Ib, the zone of termination of the major association fiber system within the olfactory cortex. A prominent granular reaction, which does not correspond to any known long axon system, is found in all layers of the cortex, although it is concentrated at the superficial edge of layer Ib and in layer II. Variation in staining in the several subdivisions of the olfactory cortex are illustrated and described. In the olfactory bulb, the most prominent staining is a relatively fine, granular reaction in the glomerular formations, which apparently corresponds to the olfactory nerve terminals. In immature rats, the Timm method stains the neuropil throughout the olfactory system, although the patterns and quality of staining differ from that found in adults. Before birth, the best-differentiated reaction is seen in glomeruli of the olfactory bulb and correlates well with the pattern of olfactory nerve ingrowth. The earliest and most prominent reaction is found in the modified glomerular complex in the caudodorsal part of the bulb. In the olfactory cortex the earliest staining occurs before birth in the posterior piriform cortex. Cortical staining is not extensive until the 1st postnatal week, and the islands of Calleja in the olfactory tubercle lack a distinct positive reaction until postnatal day 7. The staining patterns become adult-like in all parts of the olfactory cortex during the 3rd postnatal wk.