新生大鼠脊髓切片运动神经元的电生理参数测定

INTRACELLULAR RECORDING OF MEMBRANE POTENTIAL AND CURRENT FROM MOTONEURONS IN THE NEONATAL RAT SPINAL CORD SLICES

用微电极技术对新生大鼠脊髓横切薄片运动神经元(MN)进行细胞内记录,测得静息电位为-62±4mV(n=26),膜电阻为67±31MΩ,时间常数3.8±1.6ms,动作电位幅度68±7mV(n=26),阈电位-50±8mV,超射值6±4mV。灌流谷氨酸(1～30mmol/L)诱导伴膜电阻降低的缓慢去极化反应,5-羟色胺(50μmol/L)介导伴膜电导降低的电压依赖性内向电流。结果表明新生大鼠脊髓切片MN的细胞内生物电记录是一种稳定可靠的电生理学和药理学研究方法。

By the microelectrode techniques, intracellular recordings were made from motoneurons (MNs) in the neonatal rat spinal cord slices. From 26 MNs it was observed that the resting potential, input resistance and time constant was -62 ± 4 mV, 67 ± 31 MQ, 3.8 ± 1.6 ms, respectively. The amplitude, threshold level and overshoot of the direct action potential were measured as 68 ± 7 mV (n = 26), -50 ± 8 mV and 6± 4 mV. Superfusion with glutamate (1-30 mmol/ L) induced dose-dependent depolarization of MNs with decrease in input resistance. Under single electrode voltage clamp recording, the voltage-dependent inward current with decrease in membrane conductance was mediated by serotonin(50 μmol/L). The intracellular recording technique of membrane potential and current from MNs in vitro was proved to be useful in electrophysiology and pharmacology studies.