RESPONSES OF NEURONS IN SOMATOSENSORY CORTICAL AREA-II OF CATS TO HIGH-FREQUENCY VIBRATORY STIMULI DURING IONTOPHORESIS OF A GABA ANTAGONIST AND GLUTAMATE
RESPONSES OF NEURONS IN SOMATOSENSORY CORTICAL AREA-II OF CATS TO HIGH-FREQUENCY VIBRATORY STIMULI DURING IONTOPHORESIS OF A GABA ANTAGONIST AND GLUTAMATE
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DOI：
10.3109/08990228809144670
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发表时间：
1988-01-01
影响因子：
0.9
通讯作者：
BURTON, H
中科院分区：
文献类型：
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作者：
ALLOWAY, KD;SINCLAIR, RJ;BURTON, H
在第二躯体感觉皮层（SII）的猫，大力响应低振幅，高频率的振动刺激的地区映射相对于周围的躯体组织。具有这些特性的神经元被发现在前肢远端区的后部和内侧部分，并被判断为接受来自环层机械感受器的输入。在谷氨酸盐或甲碘荷包牡丹碱（BMI）的离子电渗给药期间研究这些神经元对正弦振动触觉刺激的响应，以确定这些皮层神经元的时间保真度是否由使用γ-半乳糖苷的抑制回路控制。氨基丁酸（GABA）是一种神经递质。从19个Pacinain敏感的神经元的数据进行了分析的变化，平均放电率，夹带的百分比，和模式的周期性所揭示的自相关图和间隔直方图。BMI或谷氨酸盐的离子导入在低频和高频振动刺激期间引起平均放电率显著增加。由BMI产生的活动增加的模式的特征在于夹带百分比的小而显著的减少，而谷氨酸引起的这种测量的变化较小且不太显著。自相关和间隔直方图的分析表明，BMI增加了连续刺激周期的刺激持续时间的小片段的发射的概率。
Areas in the second somatic sensory cortex (SII) of cats that responded vigorously to low-amplitude, high-frequency vibratory stimulation were mapped with respect to the surrounding somatotopic organization. Neurons with these properties were found in the posterior and medial parts of the distal forelimb zone and were judged as receiving input from Pacinian mechanoreceptors. The responses of these neurons to sinusoidal vibrotactile stimulation were studied during iontophoretic administration of glutamate or bicuculline methiodide (BMI) to determine if the temporal fidelity of these cortical neurons was controlled by inhibitory circuits that used .gamma.-aminobutyric acid (GABA) as a neurotransmitter. The data from 19 Pacinain-sensitive neurons were analyzed for changes in the mean firing rate, the percentage of entrainment, and the pattern of periodicity as revealed by autocorrelograms and interval histograms. Iontophoresis of BMI or glutamate caused significant increases in mean firing rates during low- and high-frequency virbratory stimulation. The pattern of increased activity produced by BMI was characterized by a small, yet significant, reduction in the percentage of entrainment, whereas glutamate caused smaller and fewer significant changes in this measure. Analysis of autocorrelation and interval histograms suggested that BMI increased the probability of firing on consecutive stimulus cycles in small segments of the stimulus duration.