Phase-relationship and mutual effects between circadian rhythms of ocular melatonin and dopamine in the pigeon
Phase-relationship and mutual effects between circadian rhythms of ocular melatonin and dopamine in the pigeon
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DOI：
10.1016/s0006-8993(98)00206-6
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发表时间：
1998-05-11
期刊：
影响因子：
2.9
通讯作者：
Ebihara, S
中科院分区：
文献类型：
--
作者：
Adachi, A;Nogi, T;Ebihara, S
为了研究鸽子眼部昼夜节律的机制，我们使用体内微透析同时测量了眼部褪黑激素和多巴胺。在实验1中，研究了明暗循环（LD）和连续弱光（LLdim）下眼部褪黑激素和多巴胺的昼夜节律之间的相位关系。在 LD 条件下，褪黑激素在黑暗时含量高，在光亮时含量低。另一方面，多巴胺在光明期间较高，在黑暗期间较低。在将鸡从 LD 转移到 LLdim 后，这些具有反相位关系的节律得以维持。在实验 2 中，研究了单个光脉冲对褪黑激素和多巴胺节律的影响。 CT18 的光脉冲迅速将褪黑激素的释放抑制到白天水平，而它迅速将多巴胺的释放增加到白天的水平。光脉冲还影响褪黑激素和多巴胺节律的相位，诱导两种节律的相位提前，而不改变光脉冲之前的反相位关系。在实验3中，检查了眼内注射多巴胺或褪黑激素对其昼夜节律的影响。在主观夜间注射多巴胺会抑制褪黑激素的释放，并诱导褪黑激素和多巴胺节律的光脉冲型相移。另一方面，主观日注射褪黑激素抑制多巴胺释放并诱导暗脉冲型相移。这些结果与一个或两个振荡器模型兼容，但无论哪种情况，褪黑激素和多巴胺之间的相互作用都被认为是调节鸽子眼部昼夜节律的重要机制。 (C) 1998 Elsevier Science B.V.
In order to study the mechanisms of ocular circadian rhythms in the pigeon, we measured melatonin and dopamine simultaneously from the eye using in vivo microdialysis. In experiment 1, the phase relationship between circadian rhythms of ocular melatonin and dopamine under light-dark cycles (LD) and continuous dim light (LLdim) was examined. Under LD, melatonin was high during the dark and low during the light. On the other hand dopamine was high during the Light and low during the dark. These rhythms with the anti-phase relationship were maintained after the birds were transferred from LD to LLdim. In experiment 2, effects of a single light pulse on melatonin and dopamine rhythms were examined. A light pulse at CT18 rapidly suppressed melatonin release to the daytime level, whereas it rapidly increased dopamine release to the daytime level. The light pulse also affected the phases of melatonin and dopamine rhythms, inducing phase advances of both rhythm without changing the anti-phase relationship before the Light pulse. In experiment 3, effects of an intraocular injection of dopamine or melatonin on their circadian rhythms were examined. A dopamine injection during the subjective night suppressed melatonin release and induced a light-pulse type phase shift in both melatonin and dopamine rhythms. On the other hand, a melatonin injection during the subjective day suppressed dopamine release and induced a dark-pulse type phase shift. These results are compatible with either one or two oscillator models, but the interaction between melatonin and dopamine is, in either case considered as an important mechanism regulating ocular circadian rhythms of the pigeon. (C) 1998 Elsevier Science B.V.