摘要
目的观察大鼠海马脑片盲法全细胞记录技术研究CA1区锥体神经元电压门控性Ca2+通道的动力学特征,为在海马脑片上进行神经科新药开发提供依据。方法选用出生20～30d的Wistar雄性大鼠20只,断头取脑,将海马切为厚400μm的薄片,解剖镜下选CA1区锥体神经元细胞线行盲法全细胞记录。结果大鼠海马脑片CA1区锥体神经元电压门控性Ca2+通道电流具有如下特点:①激活的阈电位偏低,为(-49±9)mV,范围为-65～-30mV(n=23)。②衰减时间常数τ值较大,且变化范围大(100～700ms)(n=12),并且衰减具有Ca2+电流幅值的依赖性。③稳态失活呈现电压依赖性,半失活电压为(-55±10)mV,斜率因子为(5.3±0.9)(n=10)。④当细胞外Ca2+浓度为2.5mmol/L时,Ca2+通道的反转电位为(55±13)mV(n=10)。⑤尾电流成分较为单一,不表现电压依赖性。另外,Ca2+电流对戊脉胺及双氢吡啶类化合物硝苯地平均不敏感。结论海马脑片CA1区锥体神经元上的Ca2+通道主要以N型为主。
AIM:To investigate the dynamic properti es of voltage-gated Ca 2+ channel of CA1pyramidal neuron in rat hippoc ampal slices by using blind w hole-cell recording techniques an d to provide basis for development of neurol ogical drugs.METHODS:20Wistar rats(20-30d years)were selected.Hippoc ampus slices of 400μm thickness were cut and pyramid neur ons at CA1area we re used for blind whole cell recording.RESULTS:The voltage-gated Ca 2+ channel of CA1pyramidal neuron in ra t hippocampal slices had following fe atures:①The threshold potential of ac-tivation was relatively lower.The mean value was(-49±9)mV with range from -65to -30mV(n=23).②Curre nt decay was Ca 2+ -dependent and its time constant (τ)was longer with a wide range from 1 00t o 700ms (n=12).③The steady-state inactivation was v oltage-dep endent and the half inactivation potential(V 1/2 )was(-55±10)mV,slope factor(k)was5.3±0.9(n=10).④Th e reversal potential(Erev)of Ca 2+ channel was(55±13)mV(n=10)when extracellular Ca 2+ concentration was2.5mmol /L.⑤Tail current,which was voltage-independ ent,primarily had only one component.In addition,Ca 2+ channel was insensitive to veri-pamil and nifedipine.
出处
《中国临床康复》
CSCD
2003年第22期3056-3058,共3页
Chinese Journal of Clinical Rehabilitation
