SPATIOTEMPORAL CONVERGENCE AND DIVERGENCE IN THE RAT S1 BARREL CORTEX
SPATIOTEMPORAL CONVERGENCE AND DIVERGENCE IN THE RAT S1 BARREL CORTEX
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DOI：
10.1002/cne.902630209
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发表时间：
1987-09-08
影响因子：
2.5
通讯作者：
FOX, K
中科院分区：
文献类型：
--
作者：
ARMSTRONGJAMES, M;FOX, K
采用1.14度的标准振动挠度对大鼠皮质桶状野细胞的感受野大小和反应强度进行了评价。这些刺激落在刺激-反应曲线的平台区。分析所有神经元对中枢-感受野内及周围所有触须的反应概率和反应潜伏期。结果表明，核上层细胞的中心感受野较小（平均1.6个触须），周围兴奋性较小（1.5个触须）；颗粒层细胞的中心感受野较小（1.4个），周围兴奋性较大（2.6个）。小颗粒层神经元具有大但弱的中心-接受野（2.6）和大的周围（3.5）。对64个第四层神经元进行了研究，通过染色损伤和细胞色素氧化酶染色确定了神经元的精确位置。间隔和桶状凹内细胞的感受野大小没有差异，但后者每次刺激主触须产生两个或更多尖峰的可能性是前者的两倍（65%对33%）。组织学分析表明，主触须在86%（64 / 55）的情况下与合适的触须同义。对三个相邻的桶（E1， E2和D1）的会聚输入的定量分析显示，接受野周围有相当大的分级重叠，尽管靠近神秘性垫的面部毛发只影响桶野边缘的细胞。个别触须对邻近不合适的桶表现出明显的不同输入，优先被引导到远间隔而不是桶中空细胞。潜伏期分析表明，40%的桶状中空细胞和48%的桶状间隔细胞对相应的振动有短潜伏期（< 10 ms）的反应。相比之下，对不适当的振动反应绝大多数是长潜伏期（10- 10- 30 ms），桶状中空细胞和间隔细胞的不适当反应只有2%和13%是短潜伏期。这些结果表明，直接投入在很大程度上反映了适当的桶。讨论了不同输入是由皮层内机制产生的可能性。
The size and response magnitude of receptive fields were evaluated for cells in the rat cortical barrel-field by using standard vibrissal deflections of 1.14.degree.. Such stimuli fell within the plateau region of stimulus-response curves. The response of all neurones to all vibrissae within and surrounding centre-receptive fields were analysed for probability and latency of response. It was found that cells in supragranular layers had small centre-receptive fields (average 1.6 vibrissae) with small excitatory surrounds (1.5 vibrissae) while cells in the granular layers had small, powerful centre-receptive fields (1.4) with moderately large excitatory surrounds (2.6). Neurones in infragranular layers possessed large but weak centre-receptive fields (2.6) with large surrounds (3.5). Sixty-four neurones in layer IV were studied, the precise locations of which were identified by using dye lesioning and cytochrome oxidase staining. There were no differences in receptive field size for cells within septa and barrel hollows, but the latter were twice as likely to produce two or more spikes per stimulus from the principal vibrissa (65% against 33%). Histological analysis showed that the principal vibrissa was synonymous with the appropriate vibrissa for the barrel on 86% (55 of 64) of occasions. A quantitative analysis of convergent input to three neighboring barrels (E1, E2 and D1) showed considerable graded overlap of receptive field surrounds, although facial hair adjacent to the mystacial pad only influenced cells on the edge of the barrel-field. Individual vibrissae exhibited significant divergent input to adjacent inappropriate barrels, being preferentially directed to distant septal rather than barrel hollow cells. An analysis of latencies showed that 40% of barrel hollow cells and 48% of barrel septal cells responded at short (< 10 ms) latencies to their appropriate vibrissa. In contrast, response to inappropriate vibrissae were overwhelmingly of long latency (10- > 30 ms), only 2% of inappropriate response from barrel hollow cells and 13% from septal cells being of short latency. These results suggest that direct inputs largely project to appropriate barrels. The possibility that divergent inputs are generated by intracortical mechanisms is discussed.