Functional organization of mouse and rat SmI barrel cortex following vibrissal damage on different postnatal days.
Functional organization of mouse and rat SmI barrel cortex following vibrissal damage on different postnatal days.
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DOI：
10.3109/07367228409144548
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
D. Simons;D. Durham;T. Woolsey
中科院分区：
文献类型：
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作者：
D. Simons;D. Durham;T. Woolsey
本研究旨在确定新生儿胡须损伤后解剖学改变的体感皮层神经元的功能特性。在小鼠和大鼠的新生儿面部触须病变改变了对侧SmI皮质桶的解剖组织。这些变化取决于外周损伤的模式和严重程度以及动物的发育年龄。为了了解这些解剖学变化的一些功能相关性，在出生后第1、3和5天的小鼠和出生后第1和5天的大鼠中，触须的中间行（C行）受损。在动物成熟后研究单个皮层单位的感受野特性。在24只小鼠和15只大鼠中，共有1，370个单位的特征在于微电极穿透，这些微电极穿过与软脑膜相切或垂直的体感皮层。在解剖学上对装置的桶和层流边界进行定位，并在组织学上评估外周损伤的程度。这些数据揭示了一个有序的代表性的感觉周边，正好与改变细胞结构组织的SmI皮质。具体而言：（1）在扩大的行B或行D桶中的单元主要响应于行B或行D晶须。(2)在第四层，单位在改变行C皮质要么不能可靠地从周边驱动，被激活的刺激疤痕组织在受损的面部行C，或驱动相邻的，完整的行B或行D晶须。(3)单位在上和颗粒层下要么没有行C代表或纳入疤痕组织在其感受野在地形正确的方式。单位刺激疤痕组织的反应是定性相似的，从完整的触须，这也激活他们引起的。(4)在SmII中，对胡须做出反应的单位具有感受野，其组织与SmI中观察到的外围代表性相匹配。(5)有没有映射的nonmystyrene垫结构的桶皮质，也没有单位与异常的多须相互作用时，考虑到层流边界。这些数据表明，新生儿的胡须损伤改变了桶的解剖结构和生理上确定的躯体位置的感官周边的代表性在一个平行的和可预测的方式。
This study was undertaken to determine the functional properties of neurons in the anatomically altered somatosensory cortex after neonatal whisker damage. In mice and rats neonatal lesions of the facial vibrissae change the anatomical organization of barrels in the contralateral SmI cortex. These changes depend on the pattern and severity of the peripheral damage and the developmental age of the animals. To understand some of the functional correlates of these anatomical changes, the middle row of vibrissae (row C) was damaged in mice on postnatal days 1, 3, and 5 and in rats on postnatal days 1 and 5. The receptive field properties of single cortical units were studied after the animals matured. In 24 mice and 15 rats a total of 1,370 units were characterized in microelectrode penetrations which passed through the somatosensory cortex either tangential or perpendicular to the pia. Units were localized anatomically with respect to both barrel and laminar boundaries, and the extent of the peripheral damage was assessed histologically. The data revealed an orderly representation of the sensory periphery that coincided with the altered cytoarchitectonic organization of the SmI cortex. Specifically: (1) Units in the enlarged row B or row D barrels responded primarily to row B or row D whiskers. (2) In layer IV, units in the altered row C cortex either could not be reliably driven from the periphery, were activated by stimulation of scar tissue in the damaged facial row C, or were driven by adjacent, intact row B or row D whiskers. (3) Units in supra- and infragranular layers either had no row C representation or incorporated scar tissue in their receptive fields in a topographically correct fashion. Responses of units to stimulation of scar tissue were qualitatively similar to those elicited from intact vibrissae, which also activated them. (4) In SmII, units that responded to whiskers had receptive fields whose organization matched the representation of the periphery observed in SmI. (5) There was no mapping of nonmystacial pad structures in the barrel cortex, and there were no units with abnormal multiwhisker interactions when laminar boundaries were taken into account. These data indicate that neonatal damage to the whiskers alters both the anatomical arrangement of the barrels and the physiologically determined somatotopic representation of the sensory periphery in a parallel and predictable fashion.