Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, No. 6, Tian Tan Xi Li, Beijing 100050, China.
Brain Res. 2012 Oct 5;1477:37-44. doi: 10.1016/j.brainres.2012.08.007. Epub 2012 Aug 10.
We investigated the changes in the levels of amino acids during high frequency stimulation (HFS) of the anterior nucleus of the thalamus (ANT) in epileptic rats, which had seizures induced by unilaterally stereotactic administration of kainic acid (KA). Thirty-six adult male Wistar rats were divided into three groups: the KA-stim group (KA rats received ipsilateral ANT stimulation), the KA-sham group (KA rats received sham stimulation) and the control group, which underwent stereotactic administration of saline and received ipsilateral ANT stimulation. Microdialysis probes were unilaterally lowered into the CA3 region of the hippocampus, but probes were implanted bilaterally in the KA-stim group. The concentrations of glutamate (Glu), taurine (Tau), aspartate (Asp) and γ-aminobutyric acid (GABA) in the dialysate samples were determined by high-performance liquid chromatography. The concentrations of Glu, Asp and Tau in the hippocampi of KA rats were significantly higher than that found in control rats; however, no difference in the concentrations of GABA were found. In the ipsilateral hippocampi (KA-injected) of rats in the KA-stim group, stimulation of the ANT caused decreases in concentrations of Glu and Asp, an increase in the concentration of GABA and no significant change in the concentration of Tau. Unilateral ANT stimulation did not influence the amino acids in the contralateral hippocampus. In control rats, extracellular Tau significantly increased during and after stimulation. This study demonstrated that unilateral ANT stimulation inhibited the hyperactivation of the excitatory process and promoted the inhibitory process in the ipsilateral hippocampus of KA rats.
我们研究了高频刺激（HFS）前丘脑核（ANT）时氨基酸水平的变化，这些大鼠因单侧立体定向给予红藻氨酸（KA）而引发癫痫发作。36 只成年雄性 Wistar 大鼠分为三组：KA 刺激组（KA 大鼠接受同侧 ANT 刺激）、KA 假刺激组（KA 大鼠接受假刺激）和对照组，它们接受立体定向给予生理盐水并接受同侧 ANT 刺激。微透析探针单侧置于海马 CA3 区，但探针在 KA 刺激组双侧植入。通过高效液相色谱法测定透析液样品中谷氨酸（Glu）、牛磺酸（Tau）、天冬氨酸（Asp）和γ-氨基丁酸（GABA）的浓度。KA 大鼠海马中 Glu、Asp 和 Tau 的浓度明显高于对照组；然而，GABA 的浓度没有差异。在 KA 刺激组大鼠同侧海马（KA 注射侧），ANT 刺激导致 Glu 和 Asp 浓度降低，GABA 浓度增加，Tau 浓度无明显变化。单侧 ANT 刺激不影响对侧海马的氨基酸。在对照组大鼠中，细胞外 Tau 在刺激期间和之后显著增加。这项研究表明，单侧 ANT 刺激抑制了 KA 大鼠同侧海马兴奋性过程的过度激活，并促进了抑制性过程。
