EXTRACELLULAR IONIC VARIATIONS DURING SPREADING DEPRESSION
EXTRACELLULAR IONIC VARIATIONS DURING SPREADING DEPRESSION
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DOI：
10.1016/0306-4522(78)90122-7
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发表时间：
1978-01-01
期刊：
影响因子：
3.3
通讯作者：
NICHOLSON, C
中科院分区：
文献类型：
--
作者：
KRAIG, RP;NICHOLSON, C
在鲶鱼（Corydoras aeneus）暴露的无脑小脑分子层扩散抑制过程中，测量了 K+、Ca2+、Na+ 和 Cl- 浓度的变化。液体离子交换器离子选择性微电极成对使用，同时监测 2 个离子浓度的变化。在细胞外空间。鲶鱼小脑中的常温扩散抑制由缓慢的负电位转变组成，该电位转变以 2-3 mV/s 的速率发展，达到-25 mV 的幅度，持续 1-6 分钟，并以 0.5-1.5 mm/min 的速率传播。 [K+]o [外部] 从扩散抑制峰值时的 2.3 - 35 mM 的静息水平上升。 20 至 40 秒后，[Ca2+]o 从 2.2 mM 下降至 0.8 mM，[Na+]o 和 [Cl-]o 分别从 149-57 mM 和 137-47 mM 下降，大约在同一时间。当 [K+]o 超过 10 mM 时，[Ca2+]o、[Na+]o 和 [Cl-]o 开始减少。这些结果确定了扩散抑制过程中细胞外空间主要离子浓度变化的幅度和时间顺序。扩散性抑郁症最早的细胞外前兆是 [K+]o 的升高。鉴于 [Na+]o 和 [Cl-]o 变化的相等性以及 [K+]o 的上升，所涉及的细胞外空间的电中性可能是通过相当于 [K+]o 上升的一些未知阴离子的净积累来维持的。或者，如果某些细胞外阴离子不渗透且细胞外空间体积减少，则不需要净积累。细胞外离子浓度的总和表明，在抑郁扩散期间，细胞外空间的离子强度降低了 > 33%。大脑似乎能够建立局部离子不均匀性并从中恢复。
Changes in the concentrations of K+, Ca2+, Na+ and Cl- were measured during spreading depression in the exposed lissencephalic cerebellar molecular layer of the catfish, Corydoras aeneus. Liquid ion exchanger ion-selective microelectrodes were used in pairs to monitor simultaneously changes in the concentrations of 2 ionic spp. in the extracellular space. Normothermic spreading depression in the catfish cerebellum consists of a slow negative potential shift that develops at a rate of 2-3 mV/s, reaches an amplitude of -25 mV, lasts 1-6 min and propagates at a rate of 0.5-1.5 mm/min. [K+]o [outside] rises from a resting level of 2.3 35 mM at the peak of spreading depression. Between 20 and 40 s later [Ca2+]o falls from 2.2 mM-0.8 mM and [Na+]o and [Cl-]o decrease from 149-57 mM and 137-47 mM, respectively, at approximately the same time. [Ca2+]o, [Na+]o and [Cl-]o decreases begin when [K+]o exceeds 10 mM. These results establish the magnitude and temporal sequence of the major ion concentration changes in extracellular space during spreading depression. The earliest extracellular precursor of spreading depression is a rise in [K+]o. In light of the equality of [Na+]o and [Cl-]o changes and the rise in [K+]o, electroneutrality in extracellular space involved may be maintained by the net accumulation of some unidentified anion equivalent to the rise in [K+]o. Alternatively, no net accumulation is needed if some extracellular anions are impermeant and the volume of extracellular space decreases. The sum of the extracellular ion concentrations suggests that the ionic strength of extracellular space decreases by > 33% during spreading depression. The brain seems to be capable of establishing and recovering from local ionic inhomogeneities.