An input-output analysis of the dorsal column nuclei.
An input-output analysis of the dorsal column nuclei.
复制标题
背柱核的输入输出分析。
DOI：
10.1016/0014-4886(81)90054-6
复制
发表时间：
1981
影响因子：
5.3
通讯作者：
Whitehorn,D
中科院分区：
文献类型：
--
作者：
Walsh,JP;Whitehorn,D
核的输入-输出（IO）关系在这里被定义为离开核的总尖峰活动作为在适当的时间间隔内测量的进入核的总活动的函数。本研究的目的是阐明这种功能的形成机制。对氯醛糖麻醉的猫进行平行研究，以提供基于诱发电位和单细胞输出测量的IO功能。两套双极电极应用于浅桡神经刺激和记录不同强度的输入活动。在一系列实验中，放置在对侧内侧丘系的双极电极提供了输出的诱发电位测量。在另一个系列中，放置在楔状核中的玻璃微吸管电极提供了单细胞输出测量。我们发现从诱发电位和合并的单细胞测量产生的平均IO曲线之间有很好的一致性。单细胞测量进一步表明，归一化IO关系的急剧上升主要是由于增加输入而招募了额外的输出细胞。出现在最大输入幅度的50%至60%处的输出饱和反映了活动细胞的数量和每个活动细胞诱发的脉冲数量的限制。输入-输出关系可以用函数y = 1 −e−kx很好地描述，这个函数是从原子核的简单饱和模型推导出来的。这个模型和我们的实验数据是一致的概念，即单个传入纤维能够激活几个输出细胞，相反，每个输出细胞从几个这样的传入纤维接收输入。
The input-output (IO) relation of a nucleus is defined here as the total spike activity leaving the nucleus as a function of the total activity entering the nucleus measured over an appropriate time interval. The purpose of this study was to elucidate the mechanisms underlying the shape of this function. Parallel studies were conducted on chloralose-anesthetized cats to provide IO functions based on both evoked potential and single cell measures of output. Two sets of bipolar electrodes applied to the superficial radial nerve were used to stimulate and record input activity of various intensities. A bipolar electrode placed in the contralateral medial lemniscus provided evoked potential measures of output in one series of experiments. Glass micropipet electrodes placed in the cuneate nucleus provided single cell measures of output in the other series. We found good agreement between the average IO curves generated from the evoked potential and pooled single cell measurements. The single cell measurements showed further that the steep rise in the normalized IO relationship is due primarily to the recruitment of additional output cells by the increasing input. The saturation of output, which appears at 50 to 60% of the maximum input magnitude, reflects a limiting of both the number of cells active and the number of impulses evoked per active cell. The input-output relationships are well described by the functiony= 1 −e−kx, derived from a simple saturation model of the nucleus. This model and our experimental data are consistent with the concept that single afferent fibers are capable of activating several output cells and, conversely, that each output cell receives input from several such afferent fibers.