Ostapoff E M, Feng J J, Morest D K
Department of Anatomy, University of Connecticut Health Center, Farmington 06030.
J Comp Neurol. 1994 Aug 1;346(1):19-42. doi: 10.1002/cne.903460103.
The present study examined the morphological cell types of neurons labeled with intracellular horseradish peroxidase injections, many of them following electrophysiological recordings in the cochlear nucleus of gerbils and chinchillas. Most of the subdivisions and neuronal types previously described in the cat were identified in the present material, including spherical and globular bushy cells, stellate, bushy multipolar, elongate, octopus, and giant cells in the ventral cochlear nucleus, and a cartwheel cell in the dorsal cochlear nucleus. In many cases these structurally distinct neurons were correlated with their characteristic responses to stimulation by sound or intracellular injection of depolarizing current. The dendritic terminals of the elongate, antenniform, and clavate cells of the posteroventral cochlear nucleus link each of these cell types with neighboring structures in distinct patterns, which may provide a basis for differences in synaptic organization. These cell types differ from each other and from the stellate cells of the anteroventral cochlear nucleus. Despite their heterogeneous morphology, most of these neurons had a regular discharge in response to stimulation (choppers). Irregularly firing neurons (primary-like) had very different structures, e.g., the spherical and globular bushy cells and the bushy multipolar neuron. They, too, represent a heterogeneous population. An onset neuron was identified as an octopus cell. This paper compares the morphological observations with the electrophysiological properties of different cell types reported in a companion paper (Feng et al. [1994] J. Comp. Neurol.). Together, these findings imply that response properties may be partially independent of neuronal structure. Morphologically distinct neurons can generate similar temporal patterns in response to simple acoustic stimuli. Nevertheless, the synaptic organization of these different neuron types, including their connections, would be expected to affect or alter the cells' responses to appropriate stimuli. The possibility is raised that membrane properties and synaptic organization complement and interact with each other.
本研究检查了用细胞内辣根过氧化物酶注射标记的神经元的形态细胞类型，其中许多是在沙土鼠和毛丝鼠的耳蜗核进行电生理记录之后进行的。在本材料中鉴定出了先前在猫中描述的大多数亚区和神经元类型，包括腹侧耳蜗核中的球形和球状浓密细胞、星状细胞、浓密多极细胞、细长细胞、章鱼状细胞和巨细胞，以及背侧耳蜗核中的车轮状细胞。在许多情况下，这些结构上不同的神经元与它们对声音刺激或细胞内注入去极化电流的特征反应相关。后腹侧耳蜗核的细长、触角状和棒状细胞的树突末端以不同的模式将这些细胞类型中的每一种与相邻结构相连，这可能为突触组织的差异提供基础。这些细胞类型彼此不同，也与前腹侧耳蜗核的星状细胞不同。尽管它们的形态各异，但这些神经元中的大多数在受到刺激时具有规则放电（斩波器）。不规则放电的神经元（初级样）具有非常不同的结构，例如球形和球状浓密细胞以及浓密多极神经元。它们也代表了一个异质群体。起始神经元被鉴定为章鱼状细胞。本文将形态学观察结果与一篇配套论文（Feng等人，[1994]《比较神经学杂志》）中报道的不同细胞类型的电生理特性进行了比较。这些发现共同表明，反应特性可能部分独立于神经元结构。形态上不同的神经元在对简单听觉刺激的反应中可以产生相似的时间模式。然而，这些不同神经元类型的突触组织，包括它们的连接，预计会影响或改变细胞对适当刺激的反应。由此提出了膜特性和突触组织相互补充和相互作用的可能性。
