Prince H K, Conn P J, Blackstone C D, Huganir R L, Levey A I
Program in Neuroscience, Emory University School of Medicine, Atlanta, Georgia 30322.
J Neurochem. 1995 Jan;64(1):462-5. doi: 10.1046/j.1471-4159.1995.64010462.x.
Alterations in glutamatergic transmission are postulated to be important in kindling and epilepsy. The levels of alpha-amino-3-hydroxy- 5-methylisoxazole-4-propionic acid (AMPA) receptor subunits (GluR1, 2, and 4) were compared in amygdala-kindled and sham-operated animals using subunit-specific antibodies and quantitative western blotting. Four limbic regions were examined: limbic forebrain, piriform cortex/amygdala, hippocampus, and entorhinal cortex. When subunit levels were examined 24 h after the last stage 5 seizure, levels of GluR2 were found to be selectively reduced in limbic forebrain (30%) and piriform cortex/amygdala (25%), with no changes in other regions examined. In addition, no changes in the other subunits were observed in any region. The decrease in GluR2 that was observed in kindled animals at 24 h was no longer present at 1 week and 1 month after the last stage 5 seizure. Because the GluR2 subunit uniquely determines the calcium permeability of these receptors and because the piriform cortex has been implicated as a source of excitatory drive for limbic seizures, reduced GluR2 expression may be important in increasing neuronal excitability in kindling-induced epilepsy, or may reflect a compensatory mechanism resulting from kindling.
谷氨酸能传递的改变被认为在点燃效应和癫痫中起重要作用。使用亚基特异性抗体和定量蛋白质免疫印迹法，比较了杏仁核点燃动物和假手术动物中α-氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）受体亚基（GluR1、2和4）的水平。检查了四个边缘区域：边缘前脑、梨状皮质/杏仁核、海马体和内嗅皮质。在最后一次5期癫痫发作后24小时检查亚基水平时，发现边缘前脑（30%）和梨状皮质/杏仁核（25%）中的GluR2水平选择性降低，而在检查的其他区域没有变化。此外，在任何区域都未观察到其他亚基的变化。在最后一次5期癫痫发作后24小时在点燃动物中观察到的GluR2减少在1周和1个月后不再存在。由于GluR2亚基独特地决定了这些受体的钙通透性，并且由于梨状皮质被认为是边缘性癫痫兴奋性驱动的来源，GluR2表达的降低可能在增加点燃诱导癫痫中的神经元兴奋性方面很重要，或者可能反映了由点燃引起的一种补偿机制。
