Organization of striate cortex of alert, trained monkeys (Macaca fascicularis): ongoing activity, stimulus selectivity, and widths of receptive field activating regions.
Organization of striate cortex of alert, trained monkeys (Macaca fascicularis): ongoing activity, stimulus selectivity, and widths of receptive field activating regions.
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DOI：
10.1152/jn.1995.74.5.2100
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发表时间：
1995-11
影响因子：
2.5
通讯作者：
D. Snodderly;Moshe Gur
中科院分区：
文献类型：
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作者：
D. Snodderly;Moshe Gur
1. 在警觉的猕猴中，当电极降低穿过纹状皮层 (V1) 时，会在一系列交替的静默区和自发活动区中遇到多单位活动。 2. 在黑暗中自发活动的单个神经元通常在光中保持持续放电。由于这两种类型的放电都是在没有刻意刺激的情况下发生的，因此我们将它们称为“持续”活动。具有持续活性的区域对应于富含细胞色素氧化酶 (CytOx) 的膝受体层 4A、4C 和 6，而相邻层 2/3、4B 和 5 几乎没有持续活性。 3.感受野激活区（AR）的宽度与细胞正在进行的活动呈正相关。具有较大 AR 的细胞优先位于富含 CytOx 的（输入）层，并且许多细胞对刺激方向没有选择性。然而，沉默层中大约 90% 的细胞具有方向选择性，并且它们通常具有较小的 AR。 4. 警觉动物的定向和运动方向选择性的层状分布与麻醉动物的早期结果一致，但 AR 宽度的层状分布不同。在警觉的猕猴中，第 4B 层中的方向选择性细胞和第 5 层中的方向选择性细胞的 AR 是 V1 中最小的。 5. 我们的研究结果表明，V1（4A、4C 和 6）的输入层具有多种 AR 宽度，包括较大的宽度。皮质处理在某些输出层（4B 和 5）中产生感受野，这些感受野仅限于具有高分辨率空间位置的小型 AR。这些结果意味着警觉动物在早期皮质处理过程中存在有效的横向和/或层间相互作用。 V1 中生成的 AR 宽度的多样性可能有助于在存在对比背景的情况下检测精细细节——这是图形-背景辨别的早期阶段。
1. In alert macaque monkeys, multiunit activity is encountered in an alternating sequence of silent and spontaneously active zones as an electrode is lowered through the striate cortex (V1). 2. Individual neurons that are spontaneously active in the dark usually have a maintained discharge in the light. Because both types of discharge occur in the absence of deliberate stimulation, we call them the "ongoing" activity. The zones with ongoing activity correspond to the cytochrome oxidase (CytOx)-rich geniculorecipient layers 4A, 4C, and 6, whereas the adjacent layers 2/3, 4B, and 5 have little ongoing activity. 3. The widths of receptive field activating regions (ARs) are positively correlated with the cells' ongoing activity. Cells with larger ARs are preferentially located in the CytOx-rich (input) layers, and many are unselective for stimulus orientation. However, approximately 90% of the cells in the silent layers are orientation selective, and they often have small ARs. 4. The laminar distribution of selectivity for orientation and direction of movement in alert animals is consistent with earlier results from anesthetized animals, but the laminar distribution of AR widths differs. In alert macaques, the ARs of direction-selective cells in layer 4B and of orientation-selective cells in layer 5 are among the smallest in V1. 5. Our findings indicate that the input layers of V1 (4A, 4C, and 6) have a diversity of AR widths, including large ones. Cortical processing produces receptive fields in some of the output layers (4B and 5) that are restricted to small ARs with high resolution of spatial position. These results imply potent lateral and/or interlaminar interactions in alert animals in early cortical processing. The diversity of AR widths generated in V1 may contribute to detection of fine detail in the presence of contrasting backgrounds--the early stages of figure-ground discrimination.