大鼠脑损伤后GABA及其受体GABA_AR的变化

Changes of GABA and its receptor GABA_AR in rats after traumatic brain injury

目的 探讨GABA及其受体GABAAR在创伤性脑损伤 (TBI)后的变化规律及其在继发性脑损害中的作用。方法 用大鼠颅脑打击伤动物模型、免疫组织化学方法 ,观察了致伤后不同时相大鼠伤侧及对侧皮层、海马的GABA及GABAARα1阳性神经元的表达变化。结果 致伤后伤侧皮层GABA/GABAARα1阳性神经元逐渐减少 ,12h降至最低 ,对侧皮层无改变 ;伤侧海马及对侧海马GABA阳性神经元逐渐减少 ,12h降至最低 ;伤侧海马GABAARα1的改变与GABA的改变一致 ,对侧海马无改变。结论 TBI后脑内抑制性神经递质GABA及其受体GABAAR的表达下调也可能是继发性脑损害的重要因素之一。

Objective To study the pattem of changes of inhibitory neurotransmitter γ aminobutyric acid (GABA) and its receptor GABA AR after traumatic brain injury (TBI) and their function in secondary brain injury. Methods The changes of GABA and GABA ARα 1 positive neurones in cortex and hippocampus at different time after TBI were observed in rat model of impact brain trauma by immunohistochemical method. Results GABA/GABA ARα 1 positive neurones reduced gradually in injured side of cortex after brain injury and droped to the bottom at 12 th hour, but cortex of opposite side had no change; GABA positive neurones reduced gradually in hippocampus of the injured side and opposite side and droped to the bottom at 12 th hour; the change of GABA ARα 1 was consistent with GABA in injured side, but had no change in opposite side of hippocampus. Conclusion The decrease of inhibitory neurotransmitter GABA and its receptor GABA AR might also be one of the important factors in secondary brain injury after TBI.