Thalamocortical interactions in the somatosensory system: interpretations of latency and cross-correlation analyses.
Thalamocortical interactions in the somatosensory system: interpretations of latency and cross-correlation analyses.
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体感系统中的丘脑皮质相互作用：潜伏期和互相关分析的解释。
DOI：
10.1152/jn.1993.70.3.892
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发表时间：
1993
影响因子：
2.5
通讯作者：
Wallace,MB
中科院分区：
文献类型：
--
作者：
Alloway,KD;Johnson,MJ;Wallace,MB
1.孤立的细胞外神经元对皮肤刺激的反应，同时记录在完整的，氟烷麻醉大鼠的腹侧基底核和初级躯体感觉皮层相应的外周代表。代表前肢多毛皮肤的丘脑和皮层神经元被一系列50或100个离散空气喷射产生的毛发运动激活。一组相应的神经元代表无毛垫的后爪被激活了类似数量的点状机械位移。2.皮质电极穿透组织学重建，和118个神经元在光滑的皮肤表示表现出皮肤反应，被归类为颗粒上，颗粒，或颗粒下组根据其层状位置。分析了皮层神经元对无毛皮肤移位反应的最小潜伏期，发现皮层不同层的最小潜伏期分布有显著差异。平均值为最小laveling在颗粒下和颗粒层分别为15.8和16.3毫秒，而颗粒上神经元的特点是最小laveling具有平均20毫秒。这些组之间的差异表明，刺激诱导的传入活动达到颗粒下和颗粒层之前，接触颗粒上神经元。还根据前20次试验期间发生的反应计算了平均椎板厚度，但这些值的皮质分布相当重叠，椎板组之间的差异无统计学意义。3.在几个记录网站，两个皮层神经元同时记录，这些匹配对的反应lavelet往往是实质性的不同，尽管在层状位置的相似性。这一结果表明，层状位置不是反应潜伏期的唯一决定因素，并且连续组织的电路分布在皮质层内以及皮质层之间。4.从302个神经元的样本中表现出皮肤反应的组织学确定的区域内的丘脑或皮质，一组143对神经元同时记录从这两个区域可用于交叉相关分析。在38个神经元对中发现了显著的丘脑-皮层相互作用。这些显着的相互作用的分析表明，丘脑皮质连接强度，神经元的功效，是两到四倍大的神经元对具有颗粒层IV的皮质细胞比具有颗粒层外皮质神经元的神经元对。有没有差异，在丘脑皮质神经元之间的连接强度对含有颗粒上或颗粒下皮质神经元。5.刺激周时间直方图显示，4%（8/195）或皮质和18%（20/107）的丘脑神经元的自发活动的刺激锁定抑制。（400字处截断摘要）
1. Isolated extracellular neuronal responses to cutaneous stimulation were simultaneously recorded from corresponding peripheral representations in the ventrobasal nucleus and primary somatosensory cortex of intact, halothane-anesthetized rats. Thalamic and cortical neurons representing hairy skin on the forelimb were activated by hair movements produced by a series of 50 or 100 discrete air jets. A corresponding set of neurons representing the glabrous pads of the hind paw were activated by a similar number of punctate mechanical displacements. 2. Cortical electrode penetrations were histologically reconstructed, and 118 neurons in the glabrous skin representation exhibited cutaneous responses that were categorized into supragranular, granular, or infragranular groups according to their laminar position. Minimum latencies of cortical neurons responding to glabrous skin displacement were analyzed, and significant differences were found in the distribution of minimum latencies for the different cortical layers. Mean values for minimum latencies in the infragranular and granular layers were 15.8 and 16.3 ms, respectively, whereas supragranular neurons were characterized by minimum latencies having a mean of 20 ms. The differences between these groups suggests that stimulus-induced afferent activity reaches infragranular and granular layers before contacting supragranular neurons. Average latencies were also calculated on responses occurring during the 1st 20 trials, but the cortical distributions of these values overlapped considerably, and differences between the laminar groups were not statistically significant. 3. In several recording sites, two cortical neurons were recorded simultaneously, and the response latencies of these matched pairs were often substantially different despite the similarity in laminar position. This result indicates that laminar location is not the only determinant of response latency and that serially organized circuits are distributed within, as well as between, cortical layers. 4. From a sample of 302 neurons exhibiting cutaneous responses within histologically identified regions of thalamus or cortex, a set of 143 pairs of neurons recorded simultaneously from both regions was available for cross-correlation analysis. Significant thalamocortical interactions were found in 38 neurons pairs. Analysis of these significant interactions revealed that thalamocortical connection strength, as measured by neuronal efficacy, was two to four times larger for neuron pairs having the cortical cell in granular layer IV than for neuron pairs having an extragranular layer cortical neuron. There was no difference in thalamocortical connection strength between neuron pairs containing supra- or infragranular cortical neurons. 5. Summed peristimulus time histograms revealed stimulus-locked inhibition of spontaneous activity in 4% (8/195) or cortical and 18% (20/107) of thalamic neurons.(ABSTRACT TRUNCATED AT 400 WORDS)