Fine-scale organization of SI (Area 3b) in the squirrel monkey revealed with intrinsic optical imaging
Fine-scale organization of SI (Area 3b) in the squirrel monkey revealed with intrinsic optical imaging
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DOI：
10.1152/jn.2001.86.6.3011
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发表时间：
2001-12-01
影响因子：
2.5
通讯作者：
Roe, AW
中科院分区：
文献类型：
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作者：
Chen, LM;Friedman, RM;Roe, AW
本研究采用光学成像技术研究了松鼠猴（Saimiri sciureus）皮质在硫喷妥钠或异氟烷麻醉下的躯体位置图和3b区压力、扑动和振动的表现。初级躯体感觉皮层的指垫的代表性进行了研究，通过刺激远端指垫（D1-D5）的无毛皮肤与聚四氟乙烯探针（3-mm直径）连接通过电枢的力反馈控制的扭矩电机。在硫喷妥钠麻醉下，响应于个体指垫的刺激（梯形压痕）获得的区域3b中的内在信号图显示局灶性激活。这些激活（范围从0.5到1.0 mm）是离散的，并且在相邻指垫表示之间表现出最小的重叠。与先前发表的地图一致，观察到指垫的躯体位置表示，从D5到D1指垫有序地从内侧到外侧进展。在异氟烷麻醉下，一般地形仍然保持，但相邻手指的指垫的代表性有较高程度的重叠比硫喷妥钠麻醉。激活区的多单位和单单位记录证实了躯体位置图。为了检查来自缓慢适应I型（SA）和快速适应I型（RA）和II型（PC）机械感受器的优先输入，我们施加了由正弦压痕组成的刺激，这些压痕产生压力（1 Hz），颤动（30 Hz）和振动（200 Hz）的感觉。在硫喷妥钠麻醉下，对这些不同刺激的激活模式在皮层上是集中的和一致的。在异氟烷下，压力、扑动和振动刺激的激活区大小和形状不同，通常包含多个病灶，但总体地形保持不变。减影和矢量图显示皮层区域（直径约250 mm）优先激活的压力，扑动和振动的感觉。多单位和单单位记录有助于解释成像图。总之，与内在信号光学成像观察到的皮质信号描绘了躯体组织的区域3b，并揭示了不同的地形皮质激活模式的压力，扑动，和振动刺激。这些模式依赖于麻醉类型。这些麻醉效果的可能关系，以躯体感觉皮层可塑性进行了讨论。
Optical imaging of intrinsic cortical activity was used to study the somatotopic map and the representation of pressure, flutter, and vibration in area 3b of the squirrel monkey (Saimiri sciureus) cortex under pentothal or isoflurane anesthesia. The representation of the fingerpads in primary somatosensory cortex was investigated by stimulating the glabrous skin of distal fingerpads (D1-D5) with Teflon probes (3-mm diam) attached through an armature to force feedback-controlled torque motors. Under pentothal anesthesia, intrinsic signal maps in area 3b obtained in response to stimulation (trapezoidal indentation) of individual fingerpads showed focal activations. These activations (ranging from 0.5 to 1.0 mm) were discrete and exhibited minimal overlap between adjacent fingerpad representations. Consistent with previously published maps, a somatotopic representation of the fingerpads was observed with an orderly medial to lateral progression from the D5 to D1 fingerpads. Under isoflurane anesthesia, general topography was still maintained, but the representation of fingerpads on adjacent fingers had higher degrees of overlap than with pentothal anesthesia. Multi- and single-unit recordings in the activation zones confirmed the somatotopic maps. To examine preferential inputs from slowly adapting type I (SA) and rapidly adapting type I (RA) and type II (PC) mechanoreceptors, we applied stimuli consisting of sinusoidal indentations that produce sensations of pressure (1 Hz), flutter (30 Hz), and vibration (200 Hz). Under pentothal anesthesia, activation patterns to these different stimuli were focal and coincided on the cortex. Under isoflurane, activation zones from pressure, flutter, and vibratory stimuli differed in size and shape and often contained multiple foci, although overall topography was maintained. Subtraction and vector maps revealed cortical areas (approximate 250-mm diam) that were preferentially activated by the sensations of pressure, flutter, and vibration. Multi- and single-unit recordings aided in the interpretation of the imaging maps. In conclusion, the cortical signals observed with intrinsic signal optical imaging delineated a somatotopic organization of area 3b and revealed different topographical cortical activation patterns for pressure, flutter, and vibratory stimuli. These patterns were dependent on anesthesia type. Possible relationships of these anesthesia effects to somatosensory cortical plasticity are discussed.