Calcium dynamics in neurons treated with toxic and non-toxic concentrations of glutamate.
Calcium dynamics in neurons treated with toxic and non-toxic concentrations of glutamate.
复制标题
用有毒和无毒浓度的谷氨酸处理的神经元中的钙动态。
作者:
M. DeCoster;M. Koenig;J. Hunter;F. Tortella
Intracellular calcium concentration ([Ca2+]i) dynamics were simultaneously monitored in multiple cultured rat neurons loaded with Fluo-3 and continuously stimulated with glutamate (GLU). Three response types were observed: 10 microM GLU caused an initial transient increase in [Ca2+]i; 20 microM a biphasic response characterized by a 150-350 s 'calcium trough' between peaks; and 40 microM an initial sustained increase in [Ca2+]i. Neurons in calcium-free medium treated with 40 microM GLU showed only an initial transient increase in [Ca2+]i, demonstrating the dependence of sustained secondary increases in [Ca2+]i on extracellular calcium sources. We observed synchronized responses of multiple neurons within a given culture well, after GLU treatment, supporting the hypothesis that sustained influx of extracellular calcium may be stimulated by depletion of intracellular calcium and/or the release of endogenous excitatory amino acids.