Effect of propofol on excitability of pyramidal neurons in orbitofrontal cortex of mice and underlying ion channel mechanism
10.3760/cma.j.cn131073.20200110.00515
- VernacularTitle:丙泊酚对小鼠眶额叶皮层锥体神经元兴奋性的影响及其离子通道机制
- Author:
Weixing DING
1
;
Yang CHEN
;
Ming ZHANG
;
Bin YI
;
Kaizhi LU
;
Jinquan WANG
Author Information
1. 云南省曲靖市第二人民医院麻醉科 655000
- From:
Chinese Journal of Anesthesiology
2020;40(5):577-580
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the effect of propofol on excitability of pyramidal neurons in orbitofrontal cortex of mice and the underlying ion channel mechanism.Methods:Brain slices of 400 μm thickness from healthy male C57 mice (aged 8-12 weeks)were prepared.This experiment was performed in two parts.Part Ⅰ The brain slices were divided into 2 groups ( n=7 each) based on the random number table method: control group (C group) and propofol group (P group). Cells were perfused with vehicle in group C and with 10 μmol/L propofol in group P. Part Ⅱ The brain slices were divided into 5 groups ( n=8 each) using the random number table method: propofol group (P group), hyperpolarization-activated non-selective cation channel antagonist ZD7288 plus propofol group (Z + P group), inward rectifier potassium channel antagonist topiramate plus propofol group(T + P group), transient activation of voltage-gated potassium channel antagonist 4-aminopyridine (4AP) plus propofol group (A + P group), and delayed activation of voltage-gated potassium channel antagonist tetraethylammonium (TEA) plus propofol group (TEA + P group). Cells were perfused with 10 μmol/L propofol for 2 min in P group, with 5 μmol/L ZD7288 and 10 μmol/L melatonin for 2 min in Z+ P group, with 5 μmol/L topiramate and 10 μmol/L propofol for 2 min in T + P group, with 10 μ mol/L 4-aminopyridine and 10 μmol/L propofol for 2 min in A+ P group, and with 10 μmol/L TEA and 10 μmol/L propofol for 2 min in TEA+ P group.The whole-cell currents, membrane potential and discharge frequency of pyramidal neurons in the orbitofrontal cortex were recorded by whole-cell patch-clamp. Results:Part Ⅰ Compared with C group, whole-cell currents were significantly increased, and the membrane potential and discharge frequency were decreased in P group ( P<0.01). Part Ⅱ Compared with P group, no significant change was found in the whole-cell currents, membrane potentials and discharge frequency in Z+ P group, T+ P group and A+ P group ( P>0.05), and the whole-cell currents were significantly decreased, and the membrane potentials and discharge frequency were increased in TEA+ P group ( P<0.05). Conclusion:Propofol can inhibit the excitability of pyramidal neurons in the orbitofrontal cortex, and the mechanism is related to activating delayed activation of voltage-gated potassium channels in mice.
