Nickell J, Pomerleau F, Allen J, Gerhardt G A
Department of Anatomy and Neurobiology, Center for Sensor Technology and the Morris K. Udall Parkinson's Disease Research Center of Excellence, University of Kentucky Chandler Medical Center, Lexington, KY 40536-0098, USA.
J Neural Transm (Vienna). 2005 Jan;112(1):87-96. doi: 10.1007/s00702-004-0151-x. Epub 2004 May 12.
In the present studies we used a multisite ceramic-based microelectrode for rapid (800 ms) and low level measures of L-glutamate in vivo. We measured the amplitude and clearance rate of phasic changes in L-glutamate release produced by local application of potassium by a micropipette placed adjacent to the recording sites in the striatum of young (6 month), late middle aged (18 month) and aged (24 month) Fischer 344 rats. Our results showed that the amplitudes and clearance rates of potassium-evoked release of L-glutamate in the striatum were significantly decreased in aged rats as compared to the other age groups. In addition, the sensitivity of glutamate fibers to depolarization with potassium was significantly decreased in the aged rats as compared to young animals. Taken together, these data are consistent with age-related alterations in glutamate release dynamics, which may involve a compensatory mechanism for maintaining static glutamate concentrations within the striatum.
在本研究中，我们使用了一种基于陶瓷的多部位微电极，用于在体内快速（800毫秒）和低水平测量L-谷氨酸。我们通过将微量移液器局部施加钾来测量年轻（6个月）、中老年（18个月）和老年（24个月）Fischer 344大鼠纹状体中与记录部位相邻处L-谷氨酸释放的相位变化的幅度和清除率。我们的结果表明，与其他年龄组相比，老年大鼠纹状体中钾诱发的L-谷氨酸释放的幅度和清除率显著降低。此外，与年轻动物相比，老年大鼠中谷氨酸纤维对钾去极化的敏感性显著降低。综上所述，这些数据与谷氨酸释放动力学中与年龄相关的变化一致，这可能涉及一种维持纹状体内静态谷氨酸浓度的补偿机制。
