Smith P H, Rhode W S
J Comp Neurol. 1985 Jul 1;237(1):127-43. doi: 10.1002/cne.902370110.
We report on the anatomy and physiology of three fusiform cells in the dorsal cochlear nucleus (DCN) of the cat. The extra- and intracellular responses of these cells to pure tones showed features typical of the cell type. Peristimulus time histograms (PSTHs) were usually of the pauser or buildup configuration with chopping behavior noted in certain instances. Intracellular records during stimulus presentations revealed sustained depolarizations for the duration of the tone followed by a prolonged after-hyperpolarization (AHP). On rare occasions, a hyperpolarization corresponding to the pause region of the PSTH was noted. Occasionally, a stimulus-induced depolarization would be maintained after stimulus offset. Rebound excitation was also observed after the AHP. Morphologically, all three cells showed the standard fusiform cell features at the light microscopic level. The cell body gave rise to apical and basal dendritic trees. The apical tree branched frequently and displayed numerous spines distally. The basal tree had fewer branches and fewer, more irregular appendages. The axon originated from the cell body and gave rise to one or more collaterals before leaving the nucleus via the dorsal acoustic stria (DAS). At the electron microscopic (EM) level, the axon collaterals may terminate on a variety of cell types in the DCN, including fusiform cells. Their vesicles are round and the terminals closely resemble many unlabeled terminals seen on the cell body and apical and basal dendrites of our labeled fusiform cells. Terminals containing round vesicles, believed to be eighth nerve terminals, were found, with one exception, only on the basal dendrites. The spine-laden, distal apical dendrites received primarily terminals containing round vesicles, presumed to originate from the unmyelinated axons of granule cells. The cell body and unmyelinated initial segment received mostly terminals containing pleomorphic and flat vesicles, which also made up a large percentage of the dendritic input. Some relevant correlations, between the distribution of synaptic terminals and the observed physiology, may be possible.
我们报告了猫背侧耳蜗核（DCN）中三种梭形细胞的解剖结构和生理功能。这些细胞对纯音的细胞外和细胞内反应显示出该细胞类型的典型特征。刺激时间直方图（PSTH）通常呈暂停型或增强型，在某些情况下还会出现切碎行为。刺激呈现期间的细胞内记录显示，在音调持续期间出现持续去极化，随后是长时间的超极化后电位（AHP）。在极少数情况下，会观察到与PSTH暂停区域相对应的超极化。偶尔，刺激偏移后刺激诱导的去极化仍会持续。在AHP后也观察到了反弹兴奋。形态学上，所有三种细胞在光学显微镜水平上均显示出标准的梭形细胞特征。细胞体产生顶树突和基底树突。顶树突频繁分支，远端有许多棘突。基底树突分支较少，附属物较少且更不规则。轴突起源于细胞体，在通过背侧听纹（DAS）离开核之前产生一个或多个侧支。在电子显微镜（EM）水平上，轴突侧支可能终止于DCN中的多种细胞类型，包括梭形细胞。它们的囊泡是圆形的，终末与我们标记的梭形细胞的细胞体以及顶树突和基底树突上看到的许多未标记终末非常相似。发现含有圆形囊泡的终末，除一个例外，仅在基底树突上发现。充满棘突的远端顶树突主要接收含有圆形囊泡的终末，推测这些终末起源于颗粒细胞的无髓轴突。细胞体和无髓起始段主要接收含有多形性和平扁囊泡的终末，这些终末也占树突输入的很大比例。突触终末的分布与观察到的生理学之间可能存在一些相关关系。
