超声刺激小鼠伏隔核后c-Fos蛋白及结构可塑性改变的实验

Changes of c-Fos Protein and Structural Plasticity in Nucleus Accumbens of Mice after Ultrasound Stimulation

目的通过对超声刺激小鼠伏隔核(NAc)后c-Fos蛋白及结构可塑性的检测,观察超声刺激脑区后神经元激活和结构改变情况,初步探讨超声进行神经调控的机制。方法将C57 BL/6小鼠随机分为超声刺激组12只,假刺激组6只。超声刺激组使用低强度聚焦超声以固定参数刺激小鼠NAc区,连续刺激7 d后行NAc区免疫组化测定c-Fos蛋白表达、电镜下观察神经元结构可塑性改变情况;假刺激组同样以超声刺激探头照射,不开机无输出功率。结果超声刺激后NAc区神经元c-Fos的表达比例显著提高,差异有统计学意义(P <0.001)。电镜下发现超声刺激组树突棘分布稀疏,数量显著减少,形态呈蘑菇型或矮树桩样,与假刺激组相比,超声刺激后树突棘密度显著降低,差异有统计学意义(P <0.000 1),树突长度显著缩短,差异有统计学意义(P <0.000 1)。结论低强度聚焦超声可显著激活NAc脑区神经元,同时可抑制性调节神经元的结构可塑性,这证明了超声刺激具备干预与治疗脑疾病的潜能。

Objective To observe the neuronal activation and structural changes after the stimulation of the nucleus accumbens(NAc)in mice by detecting c-Fos protein and structural plasticity,and to preliminally explore the mechanism of neural regulation by ultrasound.Methods C57 BL/6 mice were randomly divided into ultrasonic stimulation group(n=12)and sham stimulation group(n=6).In the ultrasound stimulation group,low intensity focused ultrasound was used to stimulate the NAc region of mice with fixed parameters.After 7 days of continuous stimulation,the expression of c-Fos protein in the NAC region was determined by immunohistochemistry,and the changes of neuronal plasticity were observed by electron microscopy.The sham stimulation group was also irradiated with ultrasonic stimulation probe,and no output power was obtained without turning on the machine.Results All mice successfully completed the whole process of ultrasonic stimulation.The expression ratio of c-fos in NAC neurons was significantly increased after ultrasound stimulation(P<0.001).Under electron microscope,it was found that the distribution of dendritic spines in the ultrasonic stimulation group was sparse,the number of dendritic spines was significantly reduced,and the morphology was mushroom-like or dwarf stump-like.Compared with the sham stimulation group,the density of dendritic spines was significantly reduced(P<0.0001),and the length of dendrites was significantly shortened(P<0.0001).Conclusion Low intensity focused ultrasound can significantly activate neurons in NAc brain region,and inhibit and regulate the structural plasticity of neurons,which proves that ultrasound stimulation has the potential to intervene and treat brain diseases.