Response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil
Response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil
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DOI：
10.1152/jn.1996.75.4.1411
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发表时间：
1996-04-01
影响因子：
2.5
通讯作者：
Voigt, HF
中科院分区：
文献类型：
--
作者：
Davis, KA;Ding, J;Voigt, HF
1.记录了长爪沙鼠耳蜗背核单个单位的电生理反应。根据Evans和纳尔逊的响应图方案（经Young和Brownell、Young和Voigt以及Shofner和Young修改）对单元进行分类。II型单位具有类似于典型听神经调谐曲线的V形兴奋性反应图，但很少或没有自发活动（SpAc < 2.5尖峰/s），并且很少或没有对噪声的反应。I/III型单位也具有V形兴奋性图和SpAc < 2.5尖峰/秒，但对噪声具有兴奋性反应。III型单位具有V形兴奋性图，具有抑制性边带，SpAc > 2.5尖峰/s，并且对噪音具有兴奋性反应。IV-T型单位通常也有一个V形的兴奋性地图与抑制边带，但有一个高度非单调的速率与水平的反应，最佳频率（BF）的音调像IV型单位，SpAc > 2.5尖峰/秒，和兴奋性反应的噪音。IV型单位在BF、SpAc > 2.5尖峰/秒的兴奋岛上方具有主要抑制反应图，并且对噪声具有兴奋反应。我们目前的结果为133个单位记录与玻璃微量吸管电极。本研究的目的是建立该物种的规范反应图数据库，用于正在进行的结构/功能和相关性研究。2.在去大脑猫中发现的主要类型的单位（II型，I/III型，III型，IV-T型和IV型）在去大脑沙鼠中发现。然而，在去脑沙鼠中遇到的II型（7.5%）和IV型（11.3%）单位的百分比较小，III型单位的百分比（62.4%）大于去脑猫。相比之下，Shofner和Young使用金属电极发现了18.5%的II型单位，30.6%的IV型单位和23.1%的III型单位。在沙鼠中描述了两种新的单位亚型：III-i型和IV-I型单位。类型III-i单元类似于类型III单元，除了类型III-i单元被低水平的噪声抑制并且被高水平的噪声激发，而类型III单元对噪声具有严格的激发反应。IV-i型单位类似于IV型单位，不同之处在于IV-i型单位被低水平的噪声激发，并被高水平的噪声抑制，而IV型单位对噪声具有严格的兴奋性反应。III-i型单位与30%的III型人群相似，IV-i型单位与50%的IV型人群相似。基于经典的II型单位的缺乏和III-i型单位和Ni型单位对宽带噪声的相互反应，我们假设某些沙鼠的III-i型单位与猫的TI型单位是相同的细胞类型和具有相似的突触连接.类型II和类型I/III单元基于它们的相对噪声响应rho和超出第一最大值的BF音调速率对电平函数的归一化斜率两者而彼此区分。以前，II型单位被定义为rho值0.3的非自发活动单位，并且速率-水平曲线始终是非单调的，归一化斜率大于-0.007/dB。I/III型单位的平均rho值为0.54，尽管有一些值
1. The electrophysiological responses of single units in the dorsal cochlear nucleus of unanesthetized decerebrate Mongolian gerbil (Meriones unguiculatus) were recorded. Units were classified according to the response map scheme of Evans and Nelson as modified by Young and Brownell, Young and Voigt, and Shofner and Young. Type II units have a V-shaped excitatory response map similar to typical auditory nerve tuning curves but little or no spontaneous activity (SpAc < 2.5 spikes/s) and little or no response to noise. Type I/III units also have a V-shaped excitatory map and SpAc < 2.5 spikes/s, but have an excitatory response to noise. Type III units have a V-shaped excitatory map with inhibitory sidebands, SpAc > 2.5 spikes/s, and an excitatory response to noise. Type IV-T units typically also have a V-shaped excitatory map with inhibitory sidebands, but have a highly nonmonotonic rate versus level response to best frequency (BF) tones like type IV units, SpAc > 2.5 spikes/s, and an excitatory response to noise. Type IV units have a predominantly inhibitory response map above an island of excitation at BF, SpAc > 2.5 spikes/s, and an excitatory response to noise. We present results for 133 units recorded with glass micropipette electrodes. The purpose of this study was to establish a normative response map data base in this species for ongoing structure/function and correlation studies.2. The major types of units (type II, type I/III, type III, type IV-T, and type IV) found in decerebrate cat are found in decerebrate gerbil. However, the percentages of type II (7.5%) and type IV (11.3%) units encountered are smaller and the percentage of type III (62.4%) units is larger in decerebrate gerbil than in decerebrate cat. In comparison, Shofner and Young found 18.5% type II units, 30.6% type IV units, and 23.1% type III units using metal electrodes.3. Two new unit subtypes are described in gerbil: type III-i and type IV-I units. Type III-i units are similar to type III units except that type III-i units are inhibited by low levels of noise and excited by high levels of noise whereas type III units have strictly excitatory responses to noise. Type IV-i units are similar to type IV units except that type IV-i units are excited by low levels of noise and become inhibited by high levels of noise whereas type IV units have strictly excitatory responses to noise. Type III-i units are similar to 30% of the type III population and type IV-i units are similar to 50% of the type IV population.4. On the basis of the paucity of classic type II units and the reciprocal responses to broadband noise of type III-i and type Ni units, we postulate that some gerbil type III-i units are the same cell type and have similar synaptic connections as cat type TI units.5. Type II and type I/III units are distinguished from one another on the basis of both their relative noise response, rho, and the normalized slope of the BF tone rate versus level functions beyond the first maximum. Previously, type II units were defined to be those nonspontaneously active units with rho values 0.3, and the rate-level curves are consistently nonmonotonic with normalized slopes steeper than than -0.007/dB. The average rho value for type I/III units is 0.54, although a few values are