Social isolation attenuates rat forebrain 5‐HT release induced by KCl stimulation and exposure to a novel environment
Social isolation attenuates rat forebrain 5‐HT release induced by KCl stimulation and exposure to a novel environment
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DOI：
10.1097/00008877-199306000-00005
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发表时间：
1993-06
影响因子：
1.6
通讯作者：
M. Bickerdike;I. K. Wright;C. Marsden
中科院分区：
文献类型：
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作者：
M. Bickerdike;I. K. Wright;C. Marsden
采用微透析技术研究了隔离饲养大鼠与群居饲养大鼠体内5 - 羟色胺（5 - HT）的释放情况。采用两种方法刺激5 - HT释放：向水合氯醛麻醉大鼠的额叶皮质局部注射氯化钾，以及让自由活动的大鼠暴露于新环境（高架十字迷宫）中。在氯化钾刺激的情况下，将微透析探头植入额叶皮质；在暴露于新环境的情况下，将其植入腹侧海马，并用人工脑脊液（1 μl/min）灌注。每20分钟收集一次透析样本，通过高效液相色谱 - 电化学检测法分析5 - HT和5 - 羟吲哚乙酸（5 - HIAA）。在群居饲养的大鼠中，氯化钾注射（1 μl，100 mM）以及在高架十字迷宫中停留20分钟均使细胞外5 - HT显著增加。在隔离饲养的大鼠中，既未观察到氯化钾诱导的细胞外5 - HT增加，也未观察到暴露于高架十字迷宫时的增加。在两种实验方案中，群居饲养或隔离饲养的大鼠透析液中的5 - HIAA均未受影响。这些结果表明，隔离饲养的大鼠释放5 - HT的突触前神经元功能降低。
The technique of microdialysis was employed to investigate in vivo 5-hydroxytryptamine (5-HT) release in isolation-reared rats compared with socially reared rats. Two methods were employed to stimulate 5-HT release: local KCl injection into the frontal cortex of chloral hydrate anaesthetized rats, and the exposure of freely moving rats to a novel environment (the elevated x-maze). Microdialysis probes were implanted into the frontal cortex in the case of KCl stimulation and the ventral hippocampus in the case of exposure to the novel environment, and perfused with artificial CSF (1 μl/min). Dialysis samples were collected every 20 min and analysed for 5-HT and 5-hydroxyindole acetic acid (5-HIAA) by HPLC with electrochemical detection. Both KCl injection (1 μl, 100 mM) and a 20 min period on the elevated x-maze produced a significant increase in extracellular 5-HT in the socially reared rats. Neither the increase in extracellular 5-HT induced by KCl nor the increase on exposure to the elevated x-maze were observed in the isolation-reared rats. Dialysate 5-HIAA was not affected in socially reared or isolation-reared rats, in either protocol. These results suggest that isolation-reared rats have a reduced presynaptic neuronal function to release 5-HT.