MPTP致小鼠黑质致密部多巴胺能神经元损伤及定量研究

目的建立正常小鼠黑质致密部部位-细胞数量标准曲线,并以之判定MPTP损伤的小鼠PD模型中多巴胺能神经元的损失.方法根据小鼠大脑解剖图谱观察小鼠黑质致密部的走向,酪氨酸羟化酶免疫组化染色显示正常小鼠大脑黑质致密部及多巴胺能神经元;观察计数MPTP处理小鼠的大脑黑质致密部多巴胺能神经元,与正常小鼠的相似部位进行比较.结果建立了正常小鼠黑质致密部部位-细胞数量分布图,利用曲线对MPTP处理小鼠所得到的切片进行分析,发现样本中多巴胺能神经元明显减少,证明判定方法可行而有效.结论本实验成功建立了MPTP致小鼠黑质致密部多巴胺神经元损伤模型,并对其损伤判定进行了标准化.

Quantitative study on loss of dopaminergic neurons in SNpc of C57/BL6 mice induced by MPTP

Objective To observe the distribution of dopaminergic neurons in SNpc and to establish standard curve in normal mice so as to measure the changes of dopaminergic neurons in number in SNpc of the mice toxicated with MPTP. Methods Ten male C57BL6 mice aged 8-12 weeks, weight 20-22 g, were randomized to receive 20 mg/kg MPTP or physical saline every 3 h for 4 times, then killed 7 d later. The mouse mesocerebrum was taken out and fixed, frozen, sectioned. All sections containing SNpc were observed under the guide of mouse brain atlas. Every other sections were chosen to stain tyrosine hydroxylase (TH) to show dopaminergic neurons immunohistochemically. The TH positive cells in SNpc were counted in each section and the standard curve was established. Results The standard curve of SNpc compact part position and TH positive cells was established. By comparing the standard curves for the MPTP intoxicated mice and the saline mice, TH positive cells in SNpc from MPTP toxicated mice decreased significantly, which confirmed the validity and feasibility of the standard curve. Conclusion The establishment of standard curve greatly facilitates the comparison of specimen from different groups and makes the assessment of dopaminergic neuron loss more accurate and efficient. The standard curve can serve as an excellent reference curve for the assessment of dopaminergic neurons in SNpc in normal C57BL6 mice.