背景:本研究旨在研究单侧迷路切除术(UL)对大鼠前庭内侧核(MVN)单胺类神经递质的影响。
方法:利用成年Sprague-Dawley大鼠通过UL建立前庭损伤动物模型。使用前庭行为测试评估模型建立和恢复过程的成功。包括自发性眼球震颤,姿势不对称,和平衡木测试。此外,免疫荧光法检测c-Fos蛋白在MVN中的表达水平。此外,单胺类神经递质表达水平的变化,包括5-羟色胺(5-HT),去甲肾上腺素(NE),多巴胺(DA),和MVN中的组胺,在UL后的不同时间点使用高效液相色谱(HPLC)进行分析(4小时,8h,1天,2天,4天,和7天)。
结果:与假手术对照组相比,UL组在UL后4小时表现出最明显的前庭损伤症状,在4天显著下降,7天几乎完全恢复。免疫荧光结果显示,在UL-4h后,MVN中c-Fos表达显著上调,作为神经元活动增强的可靠指标。与假手术组相比,HPLC分析显示,UL组同病MVN中5-HT和NE的水平在UL后4天内显著升高,在1天和2天达到顶峰,分别。DA在UL后7天的不同时间点显示出增加趋势,而组胺水平仅在UL后1天显着增加。
结论:UL诱导的大鼠MVN早期代偿期单胺类神经递质的动态变化可能与MVN对中枢前庭代偿机制的调节有关。
This study aimed to investigate the effects of unilateral labyrinthectomy (UL) on monoamine neurotransmitters in the medial vestibular nucleus (MVN) of rats.
Adult Sprague-Dawley rats were utilized for the vestibular impaired animal model through UL. The success of the model establishment and the recovery process were evaluated using vestibular behavioral tests, including spontaneous nystagmus, postural asymmetry, and balance beam test. Additionally, the expression levels of c-Fos protein in the MVN were assessed by immunofluorescence. Furthermore, changes in the expression levels of monoamine neurotransmitters, including 5-hydroxytryptamine (5-HT), norepinephrine (NE), dopamine (DA), and histamine in the MVN, were analyzed using high-performance liquid chromatography (HPLC) at different time points after UL (4 h, 8 h, 1 day, 2 days, 4 days, and 7 days).
Compared to the sham control group, the UL group exhibited the most pronounced vestibular impairment symptoms at 4 h post-UL, which significantly decreased at 4 days and almost fully recovered by 7 days. Immunofluorescence results showed a notable upregulation of c-Fos expression in the MVN subsequent to the UL-4 h, serving as a reliable indicator of heightened neuronal activity. In comparison with the sham group, HPLC analysis showed that the levels of 5-HT and NE in the ipsilesional MVN of the UL group were significantly elevated within 4 days after UL, and peaked on 1 day and 2 days, respectively. DA showed an increasing trend at different time points up to 7 days post-UL, while histamine levels significantly increased only at 1 day post-UL.
UL-induced dynamic changes in monoamine neurotransmitters during the early compensation period in the rat MVN may be associated with the regulation of the central vestibular compensation mechanism by the MVN.