用光学成像研究前庭核神经元谷氨酸受体的兴奋性传导  

Study on excitability transmission of glutamate receptor in vestibular nucleus by optical imaging

作　　者：杨仕明[1] 杨伟炎[1] 顾瑞[1] 韩东一[1] 山下敏夫[2] 

机构地区：[1]解放军总医院,北京100853 [2]日本关西医科大学耳鼻咽喉科

出　　处：《解放军医学杂志》2004年第5期396-399,共4页Medical Journal of Chinese People's Liberation Army

基　　金：国家自然科学基金 (编号 30 0 0 0 1 89);军队"十五"科研基金 (编号0 1Q0 50 );回国人员启动基金 (编号教外司留 [1 999] 363号 );解放军总医院"中青年学科带头人"人才工程基金资助课题

摘　　要：目的　在神经细胞群的水平上二维动态观测前庭核 (VN)神经元兴奋性谷氨酸递质受体的传导机制。方法　自新生小鼠制备脑干切片 ,用吸光性电压敏感染料RH 15 5染色 ,并成像于 16× 16elementsPhotodiodeArrays光学记录系统 ,电刺激前庭神经断端。为了观察谷氨酸是否为前庭核神经元的兴奋性递质 ,用受体拮抗剂 (NMDA受体拮抗剂APV ,non NMDA受体拮抗剂CNQX)灌流脑片。结果　电刺激前庭神经断端后光学记录显示兴奋传导至VN区域 ;神经兴奋有激发延迟和高峰延迟 ;光学记录可以同步观察氨基酸拮抗剂对多个神经元核团兴奋性传递的作用 ,NMDA受体拮抗剂APV和non NMDA受体拮抗剂CNQX对兴奋性突触后电位 (EPSP)的抑制作用。APV和CNQX灌流后神经元的EPSP被抑制 ,减低比率分别为 6 4 9%± 9 0 6 %和 35 1%± 9 0 6 % (n =18)。结论　光学记录膜电位方法可以在神经细胞群的水平上直观观察VN神经电活动的时空二维方式及其兴奋性突触传递过程 ;谷氨酸是VN的神经元EP SP传导的兴奋性递质 ;谷氨酸NMDA和non NMDA受体均参与介导VN神经元EPSP。Objective To explore the spatiotemporal patterns of the glutamatergic transmission in vestibular nucleus. Methods The brainstem slices were prepared from postnatal 1-5-day mice. The slices were stained with RH155, which was a light-absorbent voltage-sensitive dye, for 20 min. A multiple-site optical recording system was used for optical imaging of the evoked responses after electrical stimulation to the vestibular nerve. Results The spatiotemporal patterns of excitatory propagation in VN were illustrated. The effects of glutamate antagonist in VN after being bathed in APV (100mol/L, NMDA receptor antagonist) or CNQX (10mol/L, non-NMDA receptor antagonist) were observed in the postnatal 1 to 3 day-mouse brainstem slices. Our data showed that the percentage of APV sensitivity ranged from 50% to 84.2%, with a mean of 64.9%±9.06% (n=18). The percentage of CNQX sensitivity ranged from 15.8% to 50%, with a mean of 35.1%±9.06% (n=18). Conclusion The study indicated that the use of optical recording for revealing visually the synaptic transmission of afferent input in VN in brainstem was feasible. Both NMDA and non-NMDA receptor were sensitive to the neuronal transmission of EPSP in VN, but the NMDA sensibility to EPSP was higher than that of non-NMDA in newborn mice.

关 键 词：光学记录 电压敏感染料 前庭核 NMDA受体 non-NMDA受体 

分 类 号：R764[医药卫生—耳鼻咽喉科]