低氧预处理重塑大脑皮层兴奋/抑制平衡

Hypoxic preconditioning remodeling the balance between excitation and inhibition in cortex

目的观察急性低氧和重复低氧预处理对小鼠大脑皮层组织兴奋性与抑制性氨基酸含量的影响,初步探讨低氧预处理保护神经组织的机制。方法制备急性低氧与重复低氧预处理小鼠模型,低氧处理结束后急性分离小鼠大脑皮层组织,制备脑匀浆提取液。应用高效液相荧光检测法,分别检测大脑皮层组织兴奋性/抑制性氨基酸神经递质含量。结果急性低氧可显著增加大脑皮层组织谷氨酸的含量,并降低抑制性氨基酸甘氨酸的含量,谷氨酸与甘氨酸含量之比由对照组的2.5上升到7.2,兴奋与抑制氨基酸递质失衡。重复低氧预处理显著增加大脑皮层组织谷氨酸的含量的同时,甘氨酸含量也显著增加,谷氨酸与甘氨酸含量之比为1.7,向对照组靠拢。结论重复低氧预处理可通过重塑低氧组织的兴奋与抑制平衡,使低氧组织处于相对的稳态,利于神经细胞的生存。

[ Objective] To investigate the effect of acute hypoxia and repetitive hypoxic preconditioning on the contents of excitatory amino acid neurotransmitter and inhibitory amino acid neurotransmitter, the underlying mechanism was fundamentally explored. [Methods] The acute hypoxic and repeated hypoxic preconditioned mice model were prepared. The biochemistry techniques of high performance liquid chromatography were applied to determine the contents of excitatory and inhibitory amino acid neurotransmitter in cortex of mice. [ Results ] While the content of glycine was significantly decreased, the content of glutamate in cortex was significantly increased after acute hypoxia. The ratio between glutamate and glycine was increased from 2.5 in control group to 7.2 in HI group, implying disequilibrium occurred between excitation and inhibition in cortex. But in the hypoxic preconditioned mice, both the level of glutamate and glycine were increased significantly, the ratio between glutamate and glycine returned to 1.7 which closed to that of the control group. [ Conclusion ] Repetitive hypoxic preconditioning might protect brain tissue through remodeling the balance between excitation and inhibition under hypoxic condition.