Discharge patterns of neurons in the ventral nucleus of the lateral lemniscus of the unanesthetized rabbit.
Discharge patterns of neurons in the ventral nucleus of the lateral lemniscus of the unanesthetized rabbit.
复制标题
DOI：
10.1152/jn.1999.82.3.1097
复制
发表时间：
1999-09
影响因子：
2.5
通讯作者：
R. Batra;D. Fitzpatrick
中科院分区：
文献类型：
--
作者：
R. Batra;D. Fitzpatrick
外侧丘系腹侧核 (VNLL) 是一个主要的听觉核，可向下丘发出较大的投射。尽管 VNLL 神经元的反应很突出，但尚未得到广泛研究。先前对非胆定位物种的研究使用了麻醉，众所周知，麻醉会影响放电模式。此外，对于双耳刺激敏感的神经元比例也存在分歧。本报告检查了未麻醉兔子 VNLL 中神经元对单耳和双耳刺激的反应。大多数神经元以最佳频率对对侧突发音做出反应，并具有持续或阶段性放电模式。仅少数神经元受到抑制。大多数持续神经元被归类为短潜伏期持续（SL-持续），但也有少数神经元具有长潜伏期。一些 SL 持续的神经元在其放电模式中表现出多个峰值，即它们具有“斩波”放电模式，而其他 SL 持续的神经元则没有表现出这种模式。在普通斩波神经元中，多个峰值对应于规则放电的均匀间隔的动作电位。在不寻常的斩波神经元中，与特定峰值相关的动作电位可能在任何一次刺激呈现期间都不会出现。异常斩波神经元的放电相对不规则。相位神经元有两种类型：起始型和瞬时型。起始神经元通常在音调开始时以单个动作电位做出反应，而瞬态神经元则产生一系列动作电位。瞬时神经元相对较少。大约一半的神经元也受到同侧刺激的影响。大多数受双耳影响的神经元要么对耳间时间差异（ITD）敏感，要么被对侧刺激兴奋而被同侧刺激抑制。对ITDs敏感的神经元大多为起始型，嵌入细胞核主要部分内侧的纤维束中。受同侧刺激抑制的神经元可以是持续型或发作型。持续的神经元位于主核的外围以及纤维束中。大多数单耳神经元位于 VNLL 的主要高密度部分。目前的结果表明，VNLL 包含具有异质反应集的神经元，并且许多神经元是双耳神经元。
The ventral nucleus of the lateral lemniscus (VNLL) is a major auditory nucleus that sends a large projection to the inferior colliculus. Despite its prominence, the responses of neurons in the VNLL have not been extensively studied. Previous studies in nonecholocating species have used anesthesia, which is known to affect discharge patterns. In addition, there is disagreement about the proportion of neurons that are sensitive to binaural stimulation. This report examines the responses of neurons in the VNLL of the unanesthetized rabbit to monaural and binaural stimuli. Most neurons responded to contralateral tone bursts at their best frequency and had either sustained or phasic discharge patterns. A few neurons were only inhibited. Most sustained neurons were classified as short-latency sustained (SL-sustained), but a few were of long latency. Some SL-sustained neurons exhibited multiple peaks in their discharge pattern, i.e., they had a "chopper" discharge pattern, whereas other SL-sustained neurons did not exhibit this pattern. In ordinary chopper neurons, the multiple peaks corresponded to the evenly spaced action potentials of a regular discharge. In unusual chopper neurons, the action potential associated with a particular peak could fail to occur during any one presentation of the stimulus. Unusual chopper neurons had a relatively irregular discharge. Phasic neurons were of two types: onset and transient. Onset neurons typically responded with a single action potential at the onset of the tone, whereas transient neurons produced a burst of action potentials. Transient neurons were relatively rare. About half the neurons also were influenced by ipsilateral stimulation. Most binaurally influenced neurons were either sensitive to interaural temporal disparities (ITDs) or excited by contralateral stimulation and inhibited by ipsilateral stimulation. Neurons sensitive to ITDs were mostly of the onset type and were embedded in the fiber tract medial to the main part of the nucleus. Neurons inhibited by ipsilateral stimulation could be of the sustained or onset type. The sustained neurons were located on the periphery of the main nucleus as well as in the fiber tract. Most of the monaural neurons were in the main, high-density part of VNLL. The present results demonstrate that the VNLL contains neurons with a heterogeneous set of responses, and that many of the neurons are binaural.