MPTP诱导的帕金森病模型小鼠味觉偏好变化

Changes of the taste preference in MPTP-induced mouse model of Parkinson’s disease

目的:探讨1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)对帕金森病(PD)模型小鼠味觉的影响。方法:将雄性C57BL/6J小鼠分成对照组(control)和MPTP组,通过转棒、爬杆、嗅觉和悬尾实验检测小鼠行为,组织免疫荧光染色检测小鼠黑质致密部(SNpc)多巴胺(DA)能神经元。采用双瓶偏好实验检测小鼠对蔗糖、糖精、氯化钠及奎宁溶液的偏好率。利用real time RT-PCR检测小鼠舌上皮TAS1R1、TAS1R2和TAS1R3的mRNA表达的变化。结果:与control组相比,MPTP组小鼠转棒时间显著性降低,爬杆时间、找到隐藏食物的时间以及悬尾实验中静止时间均显著增加,免疫荧光结果显示MPTP处理可显著减少SNpc的DA能神经元数量。通过双瓶偏好实验发现MPTP可诱导小鼠对蔗糖、糖精、氯化钠的偏好率增加;但对苦味剂奎宁的偏好率没有影响。qRT-PCR分析发现MPTP抑制了小鼠舌上皮味觉受体TAS1R1和TAS1R2 mRNA的表达,而对TAS1R3 mRNA的表达没有影响。结论:MPTP诱导的PD模型小鼠对蔗糖、糖精、氯化钠的饮用偏好率增加,而对奎宁的偏好率没有影响,对这些溶液偏好率的变化可能与小鼠舌上皮味觉受体基因表达变化有关。

Objective:To investigate whether taste was altered in Parkinson’s disease(PD)model mice.Methods:C57 BL/6 J mice were respectively divided into control group and MPTP treated group.The effects of MPTP on the movement and non-movement abilities were evaluated including rotarod test,pole test,olfactory test and tail hanging test.Tyrosine hydroxylase(TH)expression in dopaminergic(DA)neurons in the substantia nigra pars compacta(SNpc)was detected by immunofluorescence.The taste was detected by two-bottle preference experiments using sucrose solution,saccharin solution,sodium chloride solution and quinine solution.The mRNA expression of taste receptor family 1 subunit 1(TAS1 R1),taste receptor family 1 subunit 2(TAS1 R2)and taste receptor family 1 subunit 3(TAS1 R3)was detected by real time RT-PCR.Results:The time spent on the rotating rod was significantly reduced in PD model mice,while the time for pole test,the time for finding the hidden food,or the quiescent time in tail suspension test were significantly increased.Immunofluorescence results showed that TH-positive neurons in the SNpc were markedly decreased in MPTP-treated mice.Compared with the control group,the MPTP group mice showed higher preference for sucrose solution,saccharin solution,and sodium chloride solution.No changes were observed in bitter taste.qRT-PCR analysis showed that the mRNA expression of TAS1 R1 and TAS1 R2 were reduced in PD model mice,and the mRNA expression of TAS1 R3 was not altered.Conclusion:MPTP-induced PD model mice showed increased preference rate for sucrose,saccharin and sodium chloride solutions.These PD model mice showed no changes in preference for quinine solution.These changes might be due to the decreased expression in TAS1 R1 and TAS1 R2.