Circadian modulation of melanopsin-driven light response in rat ganglion-cell photoreceptors.
Circadian modulation of melanopsin-driven light response in rat ganglion-cell photoreceptors.
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DOI：
10.1177/0748730409343767
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发表时间：
2009-10
影响因子：
3.5
通讯作者：
Berson DM
中科院分区：
文献类型：
--
作者：
Weng S;Wong KY;Berson DM
固有的光敏性视网膜神经节细胞(IpRGCs)投射到视交叉上核(SCN)，对于生理和行为中全球昼夜节律的正常光携带是必不可少的。光对中央时钟的影响取决于昼夜节律阶段，视网膜本身包含内在的昼夜节律振荡器，可以改变其对光的敏感性。这增加了ipRGC以及视网膜下丘脑束中的光摄取信号受到昼夜节律调节的可能性。尽管据报道，ipRGC的光色素黑素在表达上表现出昼夜变化，但还没有直接测试ipRGC的敏感性受昼夜节律控制的假设。在这里，我们通过使用多电极阵列(MEA)记录来测量大鼠ipRGC在四个昼夜时间(CT)的本征光响应的灵敏度来提供这样的测试。我们几乎没有观察到内在ipRGC光反应阈值的昼夜节律调制。然而，我们确实观察到，非常明亮的光在主观夜晚(CT12-13)比在其他昼夜阶段诱发的尖峰明显更多。因此，黑素驱动的反应的增益在清晨略有增加，大致在黑素合成被认为升高的昼夜阶段。然而，这种增益变化可能太小，不能对塑造行为光卷吸的相响应曲线有太大贡献。
Intrinsically photosensitive retinal ganglion cells (ipRGCs) project to the suprachiasmatic nucleus (SCN), and are essential for normal photic entrainment of global circadian rhythms in physiology and behavior. The effect of light on the central clock is dependent on circadian phase, and the retina itself contains intrinsic circadian oscillators that can alter its sensitivity to light. This raises the possibility that the ipRGCs, and hence the photoentraining signals in the retinohypothalamic tract, are subject to circadian modulation. Although the ipRGC photopigment, melanopsin, reportedly exhibits circadian variations in expression, there has been no direct test of the hypothesis that ipRGC sensitivity is under circadian control. Here, we provide such a test by measuring the sensitivity of intrinsic photoresponses of rat ipRGCs at four circadian times (CTs) using multielectrode array (MEA) recording. We observe little if any circadian modulation in the threshold of intrinsic ipRGC photoresponses. We do observe, however, that very bright light evoked significantly more spiking early in the subjective night (CT12-13) than at other circadian phases. Thus, the gain of the melanopsin-driven response is slightly increased in the early night, at roughly the circadian phase when melanopsin synthesis is thought to be elevated. However, this gain change is probably too modest to contribute much to shape the phase response curve for behavioral photoentrainment.
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影响因子：
16.2
作者：
CAHILL, GM;BESHARSE, JC
通讯作者：
BESHARSE, JC
影响因子：
5.3
作者：
Hartwick, Andrew T. E.;Bramley, Jayne R.;Pickard, Gary E.
通讯作者：
Pickard, Gary E.
影响因子：
25
作者：
Gooley, JJ;Lu, J;Saper, CB
通讯作者：
Saper, CB
影响因子：
64.8
作者：
Gueler, Ali D.;Ecker, Jennifer L.;Hattar, Samer
通讯作者：
Hattar, Samer
影响因子：
--
作者：
BAUER, MS
通讯作者：
BAUER, MS