Melatonin regulates neuronal plasticity in the hippocampus
Melatonin regulates neuronal plasticity in the hippocampus
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DOI：
10.1002/jnr.10605
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发表时间：
2003-05-15
影响因子：
4.2
通讯作者：
Wieraszko, A
中科院分区：
文献类型：
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作者：
El-Sherif, Y;Tesoriero, J;Wieraszko, A
研究了褪黑素对低、高频电刺激和连续快速施加两个脉冲引起的海马诱发电位的影响。在确认我们以前的研究中，褪黑激素衰减了由低频刺激（0.03 Hz）触发的群体尖峰。高频刺激（HFS; 100 Hz持续1秒，每10秒三次），在对照切片中永久促进神经元兴奋性（347% +/- 32%），也能够放大褪黑激素抑制的电位（467.8% +/- 59.6%）。由于褪黑激素是一种疏水性分子，因此将其溶解并应用于乙醇中。乙醇（0.4%）本身降低了HFS诱导的增强作用的幅度（233.5% +/- 16.8%）。用两个脉冲刺激的切片显示出对第二刺激的反应的促进作用（成对脉冲促进作用; PPF），所述两个脉冲间隔具有长于15毫秒的延迟。褪黑激素（100 μ M）对PPF的影响是双相的：在加入褪黑激素后不久，PPF短暂地（5-10分钟）逆转为成对脉冲抑制（PPI），PPI逐渐恢复到稳定的PPF。乙醇（0.4%）应用没有褪黑激素只产生了边际，促进PPF的影响。两个连续施加的脉冲之间的延迟，短于13毫秒，导致对第二刺激（PPI）的响应衰减。褪黑激素（100 R，M）在15-20 min内可逆转第二电位的衰减。乙醇本身施加在0.4%的浓度暂时（5-10分钟），但显着，抑制第二电位。这些结果表明褪黑激素调节海马锥体神经元中特定形式的可塑性的能力。(C)2003 Wiley-Liss，Inc.
The influence of melatonin on hippocampal evoked potentials initiated by low- and high-frequency electrical stimulations and by two pulses applied in rapid succession was investigated. In confirmation of our previous studies, melatonin attenuated the population spike triggered by low-frequency stimulation (0.03 Hz). High-frequency stimulation (HFS; 100 Hz for 1 sec, three times every 10 sec), which in control slices permanently facilitated neuronal excitability (347% +/- 32%), was also able to amplify the melatonin-depressed potential (467.8% +/- 59.6%). Because melatonin is a hydrophobic molecule, it was dissolved and applied in ethanol. Ethanol (0.4%) by itself reduced the magnitude of HFS-induced potentiation (233.5% +/- 16.8%). The slices stimulated with two pulses separated with a delay longer than 15 msec demonstrated a facilitation of the response to the second stimuli (paired-pulse facilitation; PPF). The influence of melatonin (100 muM) on PPF was biphasic: Shortly after addition of melatonin, PPF was briefly (5-10 min) reversed to paired-pulse inhibition (PPI), which gradually returned to a stable PPF. Ethanol (0.4%) applied without melatonin exerted only a marginal, facilitatory effect on PPF. The delay between two successively applied pulses, shorter than 13 msec, resulted in attenuation of the response to the second stimuli (PPI). Melatonin (100 R,M) reversed the attenuation of the second potential within 15-20 min following its application. Ethanol applied by itself at the concentration of 0.4% temporarily (5-10 min), but significantly, depressed the second potential. These results demonstrate the ability of melatonin to modulate specific forms of plasticity in hippocampal pyramidal neurons. (C) 2003 Wiley-Liss, inc.