Spatial sensitivity in field PAF of cat auditory cortex.
Spatial sensitivity in field PAF of cat auditory cortex.
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猫听觉皮层 PAF 区域的空间敏感性。
DOI：
10.1152/jn.00980.2002
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发表时间：
2003
影响因子：
2.5
通讯作者：
Middlebrooks,JohnC
中科院分区：
文献类型：
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作者：
Stecker,GChristopher;Mickey,BrianJ;Macpherson,EwanA;Middlebrooks,JohnC
我们比较了猫听皮层两个区域[初级听觉皮层(A1)和后听域(PAF)]神经元的空间调谐特性。扬声器在水平面(方位角)360°或垂直中面(仰角)260°范围内呈现出持续时间为80ms的宽带噪声爆发。声级比单位的阈值高20到40分贝不等。我们同时记录了α-氯醛糖麻醉猫场中16个部位的神经元放电活动。我们通过检测尖峰计数和反应潜伏期对刺激位置的依赖来评估空间敏感性。此外，我们使用人工神经网络(ANN)来评估单个单位的脉冲模式和2-32个单位的集合所携带的刺激位置信息。结果表明，与A1单位相比，PAF单位之间的空间敏感性增强，偏好位置的分布更加均匀，对刺激强度的变化也有更大的耐受性。与A1单位相比，PAF单位的反应潜伏期明显更长，并且潜伏期随刺激位置的不同而变化更大。ANN分析表明，PAF的棘波模式传递的信息明显多于A1单位，主要反映了PAF的潜伏期变化所传递的信息。最后，与A1相比，PAF的信息速率随着包括在神经集成中的单元数量而增长更快。后一项发现表明，PAF中空间的群体编码更准确，这是由更多样化的神经反应类型群体实现的。
We compared the spatial tuning properties of neurons in two fields [primary auditory cortex (A1) and posterior auditory field (PAF)] of cat auditory cortex. Broadband noise bursts of 80-ms duration were presented from loudspeakers throughout 360° in the horizontal plane (azimuth) or 260° in the vertical median plane (elevation). Sound levels varied from 20 to 40 dB above units' thresholds. We recorded neural spike activity simultaneously from 16 sites in field PAF and/or A1 of α-chloralose-anesthetized cats. We assessed spatial sensitivity by examining the dependence of spike count and response latency on stimulus location. In addition, we used an artificial neural network (ANN) to assess the information about stimulus location carried by spike patterns of single units and of ensembles of 2–32 units. The results indicate increased spatial sensitivity, more uniform distributions of preferred locations, and greater tolerance to changes in stimulus intensity among PAF units relative to A1 units. Compared to A1 units, PAF units responded at significantly longer latencies, and latencies varied more strongly with stimulus location. ANN analysis revealed significantly greater information transmission by spike patterns of PAF than A1 units, primarily reflecting the information transmitted by latency variation in PAF. Finally, information rates grew more rapidly with the number of units included in neural ensembles for PAF than A1. The latter finding suggests more accurate population coding of space in PAF, made possible by a more diverse population of neural response types.