Silva E, Quiñones B, Freund N, Gonzalez L E, Hernandez L
Behavioral and Physiology Laboratory, School of Medicine, Los Andes University (ULA), Merida 5101, Venezuela.
Brain Res. 2001 Dec 27;923(1-2):45-9. doi: 10.1016/s0006-8993(01)03195-x.
Although there is evidence that the thalamus plays a remarkable role in pain processing few in vivo studies on the thalamic neurochemical correlates of pain have been done. In the present experiments a combination of capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF) and microdialysis in freely moving rats was used to measure extracellular arginine, glutamate and aspartate in the thalamus during the formalin test. Microdialysis probes were implanted in the left ventral posterolateral (VPL) nucleus of the thalamus in rats. Samples were collected every 30 s, derivatized with fluorescein isothyocyanate and injected into a CZE-LIF instrument. After nine baseline samples, a subcutaneous formalin (5%, 50 microl) injection in the right hind paw caused an increase of arginine, glutamate and aspartate that lasted for about 3 min. These increases were calcium and nerve impulse dependent. These results indicate that the release of arginine, glutamate and aspartate may mediate rapid pain neural transmission in the VPL nucleus of the thalamus.
尽管有证据表明丘脑在疼痛处理中发挥着显著作用，但关于丘脑疼痛神经化学相关性的体内研究却很少。在本实验中，采用毛细管区带电泳结合激光诱导荧光检测（CZE-LIF）和对自由活动大鼠进行微透析的方法，在福尔马林试验期间测量丘脑细胞外的精氨酸、谷氨酸和天冬氨酸。将微透析探针植入大鼠丘脑左侧腹后外侧（VPL）核。每30秒收集一次样品，用异硫氰酸荧光素衍生化后注入CZE-LIF仪器。在采集9个基线样品后，右后爪皮下注射福尔马林（5%，50微升）导致精氨酸、谷氨酸和天冬氨酸增加，持续约3分钟。这些增加依赖于钙和神经冲动。这些结果表明，精氨酸、谷氨酸和天冬氨酸的释放可能介导丘脑VPL核中快速的疼痛神经传递。
