Alterations in Uptake and Release Rates for GABA, Glutamate, and Glutamine During Biochemical Maturation of Highly Purified Cultures of Cerebral Cortical Neurons, a GABAergic Preparation
Alterations in Uptake and Release Rates for GABA, Glutamate, and Glutamine During Biochemical Maturation of Highly Purified Cultures of Cerebral Cortical Neurons, a GABAergic Preparation
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DOI：
10.1111/j.1471-4159.1984.tb12696.x
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发表时间：
1984-04
影响因子：
4.7
通讯作者：
A. Yu;E. Hertz;L. Hertz
中科院分区：
文献类型：
--
作者：
A. Yu;E. Hertz;L. Hertz
摘要：这项研究表明，从15天大的胚胎中获得的几乎均一的小鼠脑神经元培养物，至少和含有星形胶质细胞的培养物一样分化。这表现在：成年小鼠大脑皮质的谷氨酸脱羧酶活性在2周内从微不足道的水平上升到2倍，而γ-氨基丁酸的摄取率在培养的第二周增加了四倍，并达到了高于脑片的水平。在同一时期，GABA含量增加了四到五倍，达到75nmol/mg蛋白质，钾诱导的[14C]GABA外流增加变得明显。虽然发育速度快于体内，但最佳分化需要保持1周以上的培养。谷氨酸和谷氨酰胺的摄取和释放速率发生的发育变化要小得多。暴露于[14C]谷氨酸后，未见钾引起的放射性释放，谷氨酸摄取仅在GABA能发育期略有增加。这表明外源谷氨酸不是重要的GABA前体。同样，谷氨酰胺摄取在第7天到第14天之间没有改变，尽管加载谷氨酰胺后钾诱导的少量放射性释放表明部分转化为GABA。
Abstract: This study demonstrates that virtually homogenous cultures of mouse cerebral neurons, obtained from 15‐day‐old embryos, differentiate at least as well as cultures which in addition contain astrocytes. This was indicated by glutamate decarboxylase activity which within 2 weeks rose from a negligible value to twice the level in the adult mouse cerebral cortex, and by a γ‐aminobutyric acid (GABA) uptake rate which quadrupled during the second week in culture and reached higher values than in brain slices. Within the same period, the GABA content increased four to five times to 75 nmol/mg protein, and a potassium‐induced increase in [14C]GABA efflux became apparent. Although the development was faster than in vivo, optimum differentiation required maintenance of the cultures beyond the age of 1 week. Uptake and release rates for glutamate and glutamine underwent much less developmental alteration. At no time was there any potassium‐induced release of radioactivity after exposure to [14C]glutamate, and the glutamate uptake was only slightly increased during the period of GABAergic development. This indicates that exogenous glutamate is not an important GABA precursor. Similarly, glutamine uptake was unaltered between days 7 and 14, although a small potassium‐induced release of radioactivity after loading with glutamine suggests a partial conversion to GABA.