In vivo microdialysis study of excitatory and inhibitory amino acid levels in the hippocampus following penicillin-induced seizures in mature rats.
In vivo microdialysis study of excitatory and inhibitory amino acid levels in the hippocampus following penicillin-induced seizures in mature rats.
复制标题
青霉素诱导成熟大鼠癫痫发作后海马兴奋性和抑制性氨基酸水平的体内微透析研究。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Y. Lai
中科院分区：
文献类型：
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作者：
E. Shen;Y. Lai
为了探讨儿童癫痫发生的基本机制，我们进行了青霉素（PC）应用于动物模型脑的研究。将不同剂量的PC注入微透析大鼠海马，观察癫痫发作时体内兴奋性氨基酸（EAA）和抑制性氨基酸（IAA）水平的变化。局灶性应用PC后，脑脊液间质EAA和IAA水平均升高。我们发现668和1336单位的PC足以显著提高谷氨酸水平。注射PC后40分钟内，这些水平持续下降至接近正常水平。注射PC后，天冬氨酸水平很快升高，但无统计学意义，随后又几乎下降到基线水平。注射1336u PC后，IAA、r-氨基丁酸（GABA）、甘氨酸和牛磺酸水平显著升高。注射1336u PC后，脑电图记录清晰。本研究提示，海马给予适当剂量的PC可增强脑内EAA和IAA的释放，增强脑电活动的致痫性。通过体内微透析，可以在诱导性癫痫过程中研究EAA和IAA。局灶性脑化学刺激后EAA水平的升高为研究癫痫的发生提供了良好的模型。IAA水平下降的延迟可能提示癫痫发作抑制的重要现象，也值得进一步研究。
To investigate the basic mechanism of epileptogenecity in children, we undertook a study of application of penicillin (PC) to the brain of an animal model. Different doses of PC were injected into the hippocampus of Spraque-Dawley rats subjected to microdialysis to observe in vivo changes of excitatory amino acid (EAA) and inhibitory amino acid (IAA) levels during seizure. All of the EAA and IAA levels increased in the interstitial cerebrospinal fluid (CSF) after focal application of PC. We found that 668 and 1336 units of PC were enough to increase glutamate levels significantly. These levels consistently declined to nearly normal within 40 minutes after PC injection. The aspartate level increased soon after PC injection without statistical significance and then declined almost to baseline level. The IAA, r-aminobutyric acid (GABA), glycine, and taurine levels increased significantly after injection of 1336 u of PC. EEG recording of spike discharges was also well defined after the injection of 1336 u of PC. Our study suggests that an adequate PC dose to the hippocampus will enhance the release of EAA and IAA in the brain as well as epileptogenecity on EEG activity. Using in vivo microdialysis, EAA and IAA can be studied during an induced epileptic process. Elevation of EAA levels soon after focal chemical stimulation of the brain provides a good model for study of epileptogenecity. A delay in the decline of IAA levels may suggest an important phenomenon in seizure suppression and is also worthy of further study.