Larsen J O, Braendgaard H
Stereological Research Laboratory, University of Aarhus, Denmark.
Acta Neuropathol. 1995;90(3):251-6. doi: 10.1007/BF00296508.
Methyl mercury intoxication causes ataxia. Structural changes of cerebellar and peripheral nerve tissues have been described. However, it is still unclear whether the ataxia is of cerebellar or peripheral origin. To clarify this question further, the effects of methyl mercury intoxication on the numbers of granule and Purkinje cells and the volume of Purkinje cell perikarya have been evaluated with stereological methods. Rats were intoxicated with methyl mercury, at a dose of 2 mg/kg per day for 19 successive days, and the analysis was carried out 2.5 or 4.5 weeks later. The total numbers of cerebellar granule cells and Purkinje cells were estimated using an optical fractionator and the mean volume of the Purkinje cells was estimated by the vertical rotator technique. The volumes of the granular cell layer, the molecular layer and the white matter were estimated using the Cavalieri principle. The intoxicated animals developed hindlimb incoordination when held by the tail. Although pronounced axonal degeneration occurred in the peripheral nervous system, no changes were found in cerebellar cell numbers or cell sizes in either of the test groups. The absence of detectable light microscopic changes in the cerebellum indicates that the peripheral nervous system is affected prior to the cerebellum in rats intoxicated with organic mercury.
甲基汞中毒会导致共济失调。已有文献描述了小脑和周围神经组织的结构变化。然而，共济失调是源于小脑还是周围神经仍不清楚。为了进一步阐明这个问题，我们用体视学方法评估了甲基汞中毒对颗粒细胞和浦肯野细胞数量以及浦肯野细胞胞体体积的影响。给大鼠连续19天每天注射2毫克/千克的甲基汞，在2.5周或4.5周后进行分析。使用光学分割器估计小脑颗粒细胞和浦肯野细胞的总数，通过垂直旋转器技术估计浦肯野细胞的平均体积。使用卡瓦列里原理估计颗粒细胞层、分子层和白质的体积。当抓住中毒动物的尾巴时，它们会出现后肢不协调。虽然周围神经系统发生了明显的轴突变性，但在两个测试组中，小脑细胞数量或细胞大小均未发现变化。小脑在光学显微镜下未检测到明显变化，这表明在有机汞中毒的大鼠中，周围神经系统比小脑更早受到影响。
