Svensson B A, Griph S, Rastad J, Westman J
Department of Anatomy, Uppsala University, Sweden.
Brain Res. 1987 Oct 13;423(1-2):229-36. doi: 10.1016/0006-8993(87)90844-4.
A quantitative ultrastructural study has been performed of 300 labelled and the same number of unlabelled boutons in the feline lateral cervical nucleus (LCN) of 5 adult cats after cervical or lumbar injections of lectin-conjugated horseradish peroxidase and histochemical reaction with tetramethylbenzidine. On an average the labelled boutons were slightly elongated, had areas of 2.25 micron 2, mitochondrial volume fractions of 11.2% and densities of synaptic vesicles of 35.4.micron-2. The synaptic vesicles were round to flattened with a mean length of 60 nm and length/width ratios of 1.21. The labelled boutons were significantly larger and had significantly lower densities of synaptic vesicles than the unlabelled boutons. The labelled boutons constituted about 14% of the bouton volume of the investigated areas of the LCN. Most of them were axo-dendritic and about 16% synapsed with cell bodies with ultrastructural characteristics similar to the cervico-thalamic projection neurones of the LCN. The number of boutons labelled after the injections comprising 3-5 adjacent segments of the spinal cord was calculated to 6.8 X 10(6). Based on the assumption that they represented terminals of spinocervical tract cells, it was calculated that each of these cells in the lumbar cord gives rise to an average of 4400 boutons in the LCN.
对5只成年猫的猫外侧颈核（LCN）中300个标记的和同样数量未标记的终扣进行了定量超微结构研究。在颈部或腰部注射凝集素结合辣根过氧化物酶并与四甲基联苯胺进行组织化学反应后进行研究。标记终扣平均略呈细长形，面积为2.25平方微米，线粒体体积分数为11.2%，突触小泡密度为35.4个/平方微米。突触小泡呈圆形至扁平形，平均长度为60纳米，长宽比为1.21。标记终扣比未标记终扣明显更大，突触小泡密度明显更低。标记终扣约占LCN研究区域终扣体积的14%。它们大多数是轴突-树突型的，约16%与胞体形成突触，其超微结构特征与LCN的颈-丘脑投射神经元相似。注射后标记的包含脊髓3 - 5个相邻节段的终扣数量经计算为6.8×10⁶个。基于它们代表脊髓颈束细胞终末的假设，经计算腰髓中这些细胞中的每一个在LCN平均产生4400个终扣。
