Rydmark M, Berthold C H, Gatzinsky K P
MEDNET (The Computer Laboratory of the Medical Faculty) Göteborg University, Sweden.
J Neurocytol. 1998 Feb;27(2):99-108. doi: 10.1023/a:1006995205504.
We have calculated the number of paranodal Schwann cell mitochondria in adult feline ventral and dorsal lumbar spinal roots using ultrastructural serial section analysis. Distinct accumulations of paranodal mitochondria were noted in nerve fibres more than 4-5 microm in diameter. The calculated number of paranodal mitochondria increased linearly with fibre diameter from a few hundred up to 20,000-30,000 per node. A linear increase in the number of paranodal mitochondria per node also appeared as a function of nodal variables such as 'nodal axon membrane area', 'nodal Schwann cell membrane area', and 'node gap extracellular volume'. In large fibres (D = 15-18 microm), a calculated number of about 20,000 paranodal Schwann cell mitochondria were accumulated at each node of Ranvier and related to nodal axon membrane area of about 20 microm2. Our calculations indicate that, on the average, 1000 paranodal Schwann cell mitochondria with a total volume of 6.7 microm3, a total outer membrane area of 250 microm2 and a total inner membrane area of 580 microm2 projected to each microm2 of the nodal axon membrane via the nodal Schwann cell brush border.
我们使用超微结构连续切片分析方法，计算了成年猫腰段腹侧和背侧脊髓神经根中结旁施万细胞线粒体的数量。在直径超过4 - 5微米的神经纤维中，观察到结旁线粒体有明显的聚集。计算得出的结旁线粒体数量随纤维直径呈线性增加，从每个结几百个增加到20000 - 30000个。每个结的结旁线粒体数量的线性增加，也表现为诸如“结轴突膜面积”、“结施万细胞膜面积”和“结间隙细胞外体积”等结变量的函数。在大纤维（直径D = 15 - 18微米）中，每个郎飞结处计算得出约有20000个结旁施万细胞线粒体聚集，且与约20平方微米的结轴突膜面积相关。我们的计算表明，平均而言，每平方微米的结轴突膜通过结施万细胞刷状缘有1000个结旁施万细胞线粒体，其总体积为6.7立方微米，总外膜面积为250平方微米，总内膜面积为580平方微米。
