低氧对大鼠神经元电生理特性的影响

THE ROLES OF HYPOXIA ON NMDA RECEPTOR CHANNEL IN RATS

目的 :研究低氧条件对急性分离的大鼠大脑皮层神经元NMDA通道开放动力学的影响 ;方法 :运用膜片钳技术的细胞吸附式方法记录NMDA通道的单通道电流 ;结果 :在缺氧条件下 ,NMDA通道的开放增大 ,开放时间常数τ1、τ2分别由( 0 .3 2± 0 .1 3 )ms、( 3 .46± 0 .2 6)ms变为 ( 0 .89± 0 .2 2 )ms、( 8.5 4± 0 .72 )ms,关闭时间常数τ1、τ2分别由 ( 1 7.3 3± 3 .2 0 )ms、( 1 67.46± 1 8.90 )ms变为 ( 4.2 4± 2 .1 0 )ms、( 2 0 .5 0± 4.1 2 )ms;平均开放概率由 0 .1 1± 0 .0 7变为 0 .5 6± 0 .2 5 ;结论 :缺氧能提高大鼠大脑皮层神经元NMDA通道的兴奋性 。

To study the effects of hypoxia on the kinetic properties of NMDA receptor channel of the neurons in rats.;Methods: Cell-attached mode patch clamp technique was employed to record the NMDA receptor channel;Results: The open probability of NMDA receptor channel was increased after acute hypoxia compared with normal state, the open time τ1?τ2 was changed from (0.32±0.13)ms?(3.46±0.26)ms to (0.89±0.22)ms?(8.54±0.72)ms, and the close timeτ1?τ2 was from (17.33±3.20)ms?(167.46±18.90)ms to (4.24±2.10)ms?(20.50±4.12)ms.;The mean open probability was changed from 0.11±0.07 in normal state to 0.56±0.25 in hypoxia state;Conclusion: The exci tability and the open probability of NMDA receptor channel of hypothalamic neurons can be increased by hypoxia.