弓形虫慢性感染小鼠脑内包囊分布的研究

Study on the distribution of Toxoplasma cysts in the brains of chronic Toxoplasma-infected mice

目的观察弓形虫包囊在慢性感染小鼠不同脑组织内的分布情况。方法以AH株弓形虫包囊腹腔感染小鼠20只,饲养3月后取小鼠脑组织,分离出大脑皮层、海马、中脑、小脑和脑干各部分,逐一称重,用PBS液制备成脑组织匀浆(体积均为2 ml)。从每只小鼠的每种脑组织匀浆中各吸取30μl匀浆液,涂片3张,每张10μl,瑞氏染色,显微镜下(10×40)计数弓形虫包囊个数,并用方差分析比较单位浓度(mg/ml)不同脑组织的匀浆液所含包囊的个数有无显著性差异。结果单位浓度(mg/ml)不同脑组织的匀浆液所含包囊的数量有显著性差异(P<0.01),海马和大脑皮层处最多,脑干和小脑处最少。结论弓形虫包囊在慢性感染小鼠不同脑组织内的分布有显著性差异,主要集中于海马和大脑皮层处。

To investigate the distribution of Toxoplasma cysts in different parts of brains of the chronic Toxoplasma-infected mice. 20 mice were infected intraperitoneally with Toxoplasma AH strain cysts, then different parts of their brains, cerebral cortex, hippocampus, midbrain, cerebellum and brain stem, were separated and extracted carefully after 3 months of raising. Every part oi the brains was weighed and then homogenated with 2 ml of phosphate butter saline （PBS）. Three smears were made for each tube of the homogenates, 10μl for each smear. All smears were stained with Wright＇s stain and examined through microscope （10×40） to count the number of cysts. The result of the mean number of Toxoplasma cysts at mg/ml level in different parts of brains were analyzed and compared through AVONA. Statistics show a significantly difference among numbers of cysts＇ in homogenate of 5 parts of infected mice＇s brains. Toxoplasma cysts were distributed most intensively at hippocampus and cerebral cortex, while least intensively at brain stem and cerebellum. In conclusion, the distribution of Toxoplasma cysts in various parts of chronic infected brains of mice is significantly different, and a high density of cysts can be found at hippocampus and cerebral cortex.