CAJ | 학술논문

目的观察大鼠前庭内侧核神经元的膜特性及其对前庭外周模拟传入信号的放电反应,探讨前庭系统生理功能的可能机制.方法运用红外微分干涉相差技术,可视状态下对前庭内侧核神经元进行全细胞记录,按平均动作电位形状对神经元分型,比较不同类型神经元膜特性的差异.向胞内注入刺激电流以模拟头部作直线加速和匀速旋转运动时外周前庭的传入信号,观察神经元的放电反应.结果在大鼠前庭内侧核神经元可记录到放电活动,在低钙高镁人工脑脊液中放电活动仍然存在.神经元可被分为有单相后超极化及A样整流的A型(33%),有双相后超极化的B型(63%),以及同时具有或不具有以上特征的其他型(4%);A、B型神经元的部分主动膜特性存在明显差异,对同样的模拟传入信号可作出不同的反应.结论大鼠前庭内侧核神经元的放电基于其内在膜特性的自发活动;大部分神经元的放电表现为典型的A型或B型,但仍有少量非典型放电存在;A、B型神经元膜特性和放电反应特性的差异是它们执行不同生理功能的基础.
목적 관찰대서전정내측핵신경원적막특성급기대전정외주모의전입신호적방전반응,탐토전정계통생리공능적가능궤제.방법 운용홍외미분간섭상차기술,가시상태하대전정내측핵신경원진행전세포기록,안평균동작전위형상대신경원분형,비교불동류형신경원막특성적차이.향포내주입자격전류이모의두부작직선가속화균속선전운동시외주전정적전입신호,관찰신경원적방전반응.결과 재대서전정내측핵신경원가기록도방전활동,재저개고미인공뇌척액중방전활동잉연존재.신경원가피분위유단상후초겁화급A양정류적A형(33%),유쌍상후초겁화적B형(63%),이급동시구유혹불구유이상특정적기타형(4%);A、B형신경원적부분주동막특성존재명현차이,대동양적모의전입신호가작출불동적반응.결론 대서전정내측핵신경원적방전기우기내재막특성적자발활동;대부분신경원적방전표현위전형적A형혹B형,단잉유소량비전형방전존재;A、B형신경원막특성화방전반응특성적차이시타문집행불동생리공능적기출.
Objective To study the membrane properties of rat medial vestibular nucleus(MVN) neurons and their firing responses to simulated input signals of peripheral vestibular system, and to discuss how the intrinsic membrane properties contribute to physiologic functions in central vestibular system. Methods By using infrared differential interference contrast technique, whole-cell recordings were made from rat MVN neurons under direct observation. On the basis of their averaged action potential shapes, the MVN neurons were classified. Linear and non-linear currents were put into the neurons to simulate the input signals of peripheral vestibular system. The differences of intrinsic membrane properties and firing response dynamics were observed between two types. Results The discharge activities were recorded in MVN neurons, which remained in low Ca2+-high Mg2+ artificial cerebrospinal fluid (ACSF). Neurons are classified as type A (33%) characterized by a single deep after-hyperpolarization (AHP) and A-like rectification, or type B (63%) characterized by double AHP, and another two neurons with all or none of the characters. The passive membrane properties were not significantly different between type A and type B neurons, while part of active membrane properties was significantly different. Both type A and B neurons well responded to simulated current inputs, but disparities existed in response range and firing dynamics. Conclusions The discharge activities of MVN neurons were initiated by their intrinsic membrane properties. Most MVN neurons were classified as type A and B, while several showed unrepresentative firing properties. Linear and nonlinear inputs evoked a heterogeneous range of firing responses. The differences of response range and firing dynamics between neurons may determine their different physiological functions.