Blind patch clamlp studying on the properties of calcium channel of pyramidal neurons in the rat hippocampus slices

doi:10.3321/j.issn:1673-8225.2003.22.014

Abstract：AIM:To investigate the dynamic properties of voltage gated Ca2+ channel of CA1 pyramidal neuron in rat hippocampal slices by using blind whole-cell recording techniques and to provide basis for development of neurological drugs. METHODS:20 Wistar rats(20- 30 d years) were selected.Hippocampus slices of 400 μ m thickness were cut and pyramid neurons at CA1 area were used for blind whole cell recording.RESULTS:The voltage gated Ca2＋ channel of CA1 pyramidal neuron in rat hippocampal slices had following features: ① The threshold potential of activation was relatively lower. The mean value was (－ 49± 9) mV with range from － 65 to － 30 mV (n=23). ② Current decay was Ca2＋ dependent and its time constant (τ ) was longer with a wide range from 100 to 700 ms (n=12). ③ The steady-state inactivation was voltage dependent and the half inactivation potential (V1/2) was (－ 55± 10) mV, slope factor (k) was 5.3± 0.9 (n=10). ④ The reversal potential (Erev) of Ca2＋ channel was (55± 13) mV (n=10) when extracellular Ca2＋-concentration was 2.5 mmol/L.⑤ Tail current, which was voltage independent, primarily had only one component.In addition, Ca2＋-channel was insensitive to veripamil and nifedipine. CONCLUSION:N-type Ca2+ channel is the main type in CA1 pyramidal neurons in rat hippocampal slices.