SELECTIVE RELEASE OF ENDOGENOUS ZINC FROM THE HIPPOCAMPAL MOSSY FIBERS INSITU
SELECTIVE RELEASE OF ENDOGENOUS ZINC FROM THE HIPPOCAMPAL MOSSY FIBERS INSITU
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DOI：
10.1016/0006-8993(87)91355-2
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发表时间：
1987-02-24
期刊：
影响因子：
2.9
通讯作者：
BENARI, Y
中科院分区：
文献类型：
--
作者：
ANIKSZTEJN, L;CHARTON, G;BENARI, Y
本文研究了麻醉大鼠海马内源性锌的释放。推拉套管两侧引入海马和锌浓度测定原子吸收分光光度法。我们首先研究了K+诱发的锌释放的区域分布。当推拉插管位于苔藓纤维（CA 3或门）附近而不是其他区域（包括CA 1、海马伞、齿状筋膜分子层、丘脑等）时，2 min（30 mM）K+脉冲产生内源性锌的释放。在CA3中，最大释放为2000 ng/ml（脑脊液（CSF）中锌水平的200倍）。通过局部单侧注射溶解在0.6 μ l盐水溶液中的1.5 μ g秋水仙碱破坏苔藓纤维，消除了这种释放，而不影响对照（对侧）侧的释放。以1 Hz电刺激穿支通路未引起锌的释放。相反，在10 Hz时，这种刺激产生了群体尖峰的爆发和苔藓纤维中锌的显著释放（而不是海马体的其他区域）。这些实验提供了直接的证据，锌是选择性地从苔藓纤维释放。
The release of endogenous zinc was studied in the hippocampus of the anesthetized rat. Push-pull cannulae were bilaterally introduced in the hippocampus and zinc concentrations determined by atomic absorption spectrophotometry. We first studied the regional distribution of K+-evoked release of zinc. A 2 min (30 mM) K+ pulse produced a release of endogenous zinc, when the push-pull cannulae were located in the vicinity of the mossy fibers (CA3 or hilus) but not in other regions (including CA1, fimbria, molecular layer of the fascia dentata, thalamus etc...). In CA3 the maximal release was of 2000 ng/ml (200 times the levels of zinc present in the cerebrospinal fluid (CSF)). Destruction of the mossy fibers by a local unilateral injection of 1.5 .mu.g of colchicine dissolved in 0.6 .mu.l of a saline solution, eliminated this release without affecting the release in the control (contralateral) side. Electrical stimulation of the perforant path at 1 Hz did not evoke a release of zinc. In contrast at 10 Hz this stimulation produced a burst of population spike and a significant release of zinc in the mossy fibers (and not in other regions of the hippocampus). These experiments provide direct evidence that zinc is selectively released from the mossy fibers.