AXONAL ARBORIZATIONS OF LATERAL GENICULATE NEURONS IN STRIATE CORTEX OF CAT
AXONAL ARBORIZATIONS OF LATERAL GENICULATE NEURONS IN STRIATE CORTEX OF CAT
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DOI：
10.1002/cne.901820510
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发表时间：
1978-01-01
影响因子：
2.5
通讯作者：
LEVAY, S
中科院分区：
文献类型：
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作者：
FERSTER, D;LEVAY, S
将辣根过氧化物酶（HRP）注入成年猫的视放射线内。随着位置接近外侧膝状体核（LGN），酶扩散逆行沿着的膝状体皮层中继神经元的轴突，进入他们的细胞体，并与二氨基联苯胺反应后，产生高尔基体样染色的整个神经元。当注射靠近视觉皮层时，酶顺行扩散并充满17区的完整轴突分支。在LGN中，重建1型和2型中继神经元（Guillery，1966）的实例，并测量它们的轴突直径。1型神经元（被认为对应于Y细胞; LeVay和Ferster，1977）具有大直径轴突（2-3.3 μ m），而2型神经元（被认为是X细胞）具有中等大小的轴突（1-1.7 μ m）。这两种神经元类型发出轴突侧支的周膝状体核。在皮质，2种传入纤维供应第IV层。一个分布在该层的上部（IVab层），延伸一小段距离进入III层。在白色物质中测量的这些轴突的母体干的直径与1型LGN中继细胞的直径相匹配。另一种分布于IVc层。这些轴突的直径与2型LGN中继细胞的直径相匹配。这两种类型的传入纤维大多数都向第VI层发出侧支。IVab层的轴突在皮质中横向分布较广（达2 mm），终扣聚成2-5个丛，其大小和排列与眼优势柱相似。供应层IVc的轴突有一个更受限制的树枝状，通常由一个单一的丛的终扣。在C1-C3层中发现具有非常细的轴突（< 1 μ m）的LGN神经元。它们可能对应于Guillery的4型神经元。在皮质中，细直径的轴突分支于I层的上半部分。这些轴突有时在第III层的下部和第V层中有侧支。总之，本研究中观察到的皮质传入神经的分支完全解释了在LGN中注射3 H-脯氨酸后观察到的放射自显影标记模式（LeVay和吉尔伯特，1976）。1型和2型神经元作为Y-和X-细胞的鉴定通过观察到的它们的轴突直径的差异而得到加强，这与Y-和X-细胞报道的不同轴突传导速度一致。在较深的C层中存在具有非常细的轴突的细胞与报道的在这些层中存在W细胞（具有缓慢传导的轴突）一致。不同类型的膝状体中继神经元在17区有不同的层状投射。
Horseradish peroxidase (HRP) was injected into the optic radiations of adult cats. With placements close to the lateral geniculate nucleus (LGN), the enzyme diffused retrogradely along the axons of geniculocortical relay neurons, entered their cell bodies and, after reaction with diaminobenzidine, produced a Golgi-like staining of entire neurons. When the injections were made close to the visual cortex, the enzyme diffused anterogradely and filled complete axonal arborizations in area 17. In the LGN, examples of type 1 and type 2 relay neurons (Guillery, 1966) were reconstructed, and their axon diameters measured. The type 1 neurons (thought to correspond to Y-cells; LeVay and Ferster, 1977) possessed large diameter axons (2-3.3 .mu.m), while the type 2 neurons (thought to be X-cells) had medium-sized axons (1-1.7 .mu.m). Both neuron types gave off axon collaterals to the perigeniculate nucleus. In the cortex, 2 types of afferent supplied layer IV. One distributed to the upper part of the layer (layer IVab), extending a short distance into layer III. The parent trunks of these axons, measured in the white matter, had diameters matching those of type 1 LGN relay cells. The other type distributed to layer IVc. The diameters of these axons matched those of type 2 LGN relay cells. Most afferents of both types gave off collaterals to layer VI. The axons supplying layer IVab had a wide lateral spread in the cortex (up to 2 mm), and the boutons were grouped into 2-5 clumps, whose size and arrangement were similar to ocular dominance columns. The axons supplying layer IVc had a much more restricted arborization, usually consisting of a single clump of boutons. LGN neurons with very fine axons (< 1 .mu.m) were found in laminae C1-C3. They probably corresponded to Guillery''s type 4 neurons. In the cortex, fine-diameter axons arborized in the upper half of layer I. These axons sometimes had collaterals in the lower part of layer III and in layer V. Taken together, the arborizations of the cortical afferents observed in the present study account fully for the autoradiographic labeling pattern seen after 3H-proline injections into the LGN (LeVay and Gilbert, 1976). The identification of type 1 and type 2 neurons as Y- and X-cells is strengthened by the observed difference in their axon diameters, in agreement with the different axonal conduction velocities reported for Y- and X-cells. The presence of cells with very fine axons in the deeper C laminae is consistent with the reported presence of W-cells (which have slowly conducting axons) in these layers. The different classes of geniculate relay neuron have different laminar projections in area 17.