Modulatory influence of feedback projections from area 21a on neuronal activities in striate cortex of the cat.
Modulatory influence of feedback projections from area 21a on neuronal activities in striate cortex of the cat.
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DOI：
10.1093/cercor/10.12.1217
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发表时间：
2000-12
期刊：
影响因子：
3.7
通讯作者：
Chun Wang;W. Waleszczyk;W. Burke;B. Dreher
中科院分区：
文献类型：
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作者：
Chun Wang;W. Waleszczyk;W. Burke;B. Dreher
我们研究了来自纹外视皮层21 a区的“反馈”投射对猫17区神经元反应的影响，方法是将21 a区冷却到5-10 ℃，而记录部位的温度保持在36 ℃。在区域21 a冷却之前、冷却期间和复温之后测试了取向、方向和长度选择性以及对比灵敏度。总的来说，对于从视觉上对应于区域21 a的区域17的部分记录的细胞样品，“自发”活动（在1 cd/m（2）的背景照明下）和对标准对比度（15）的视觉刺激的响应性由于区域21 a的失活而显著降低。在大约一半的细胞中，区域21 a的失活基本上影响了取向调谐的锐度。然而，只有少数细胞的方向或长度选择性受到区域21 a失活的显著影响。因此，（i）来自区域21 a的反馈投射似乎主要对区域17细胞的背景活动和反应性施加兴奋性影响，（ii）只有在区域17细胞的亚组中，来自区域21 a的反馈活动似乎特异性地调节某些感受野特性。
We have examined the influence of 'feedback' projections from extrastriate visual cortical area 21a on the responses of neurons in area 17 of the cat, by cooling area 21a to 5-10 degrees C while the temperature over the recording sites was kept at 36 degrees C. Orientation, direction and length selectivities as well as contrast sensitivity were tested before and during cooling and after rewarming of area 21a. Overall, for the sample of cells recorded from the part of area 17 visuotopically corresponding to area 21a, the 'spontaneous' activity (at background illumination of 1 cd/m(2)) and the responsiveness to visual stimuli of standard contrast (15) were significantly reduced by inactivation of area 21a. In about half of the cells inactivation of area 21a affected substantially the sharpness of orientation-tuning. However, only in a minority of the cells were the direction or length selectivities significantly affected by inactivation of area 21a. Thus (i) the feedback projections from area 21a appear to exert mainly an excitatory influence on the background activity and responsiveness of area 17 cells and (ii) only in subgroups of area 17 cells does the feedback activity originating from area 21a appear to modulate specifically certain receptive field properties.