Mice with early retinal degeneration show differences in neuropeptide expression in the suprachiasmatic nucleus.
Mice with early retinal degeneration show differences in neuropeptide expression in the suprachiasmatic nucleus.
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DOI：
10.1186/1744-9081-6-36
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发表时间：
2010-07-06
期刊：
影响因子：
--
通讯作者：
Robinson DW
中科院分区：
文献类型：
--
作者：
Ruggiero L;Allen CN;Brown RL;Robinson DW
在哺乳动物中，负责产生昼夜节律的大脑时钟位于下丘脑的视交叉上核(SCN)。时钟的光捕获是通过固有的光敏性视网膜神经节细胞(IpRGCs)发生的，这些细胞的轴突通过视网膜下丘脑束投射到SCN。虽然ipRGC足以携带光，但视杆和视锥感受器也起到了作用。成年CBA/J小鼠在出生后早期表现出视杆和视锥感受器的丢失，与CBA/N对照小鼠相比，其ipRGCs的数量更多。更多的光敏细胞可能会主张增强光反应，然而，这些小鼠表现出减弱的相移行为。为了协调这些发现，我们寻找CBA/J小鼠SCN神经元中可能存在的潜在差异，这些差异可能是昼夜节律行为改变的原因。我们假设CBA/J小鼠在ipRGCs突触所在的SCN中神经肽的表达存在差异。许多SCN神经元表达血管活性肠肽(VIP)和加压素(VP)，它们在昼夜节律的产生和光携带中起着重要作用。用免疫组织化学方法观察VIP和VP在CBA/J小鼠SCN中的表达差异，并用光诱导FOS法检测了ipRGCs对SCN的视网膜神经支配程度。我们的数据显示在CBA/J小鼠的SCN中有更多的VIP和VP阳性细胞，以及更大程度的光诱导FOS表达。这些结果暗示了SCN中神经肽表达的变化，这可能是这些动物对光的昼夜反应改变的基础。
In mammals, the brain clock responsible for generating circadian rhythms is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Light entrainment of the clock occurs through intrinsically photosensitive retinal ganglion cells (ipRGCs) whose axons project to the SCN via the retinohypothalamic tract. Although ipRGCs are sufficient for photoentrainment, rod and cone photoreceptors also contribute. Adult CBA/J mice, which exhibit loss of rod and cone photoreceptors during early postnatal development, have greater numbers of ipRGCs compared to CBA/N control mice. A greater number of photosensitive cells might argue for enhanced light responses, however, these mice exhibit attenuated phase shifting behaviors. To reconcile these findings, we looked for potential differences in SCN neurons of CBA/J mice that might underly the altered circadian behaviors. We hypothesized that CBA/J mice have differences in the expression of neuropeptides in the SCN, where ipRGCs synapse. The neuropeptides vasoactive intestinal peptide (VIP) and vasopressin (VP) are expressed by many SCN neurons and play an important role in the generation of circadian rhythms and photic entrainment. Using immunohistochemistry, we looked for differences in the expression of VIP and VP in the SCN of CBA/J mice, and using a light-induced FOS assay, we also examined the degree of retinal innervation of the SCN by ipRGCs. Our data demonstrate greater numbers of VIP-and VP-positive cells in the SCN of CBA/J mice and a greater degree of light-induced FOS expression. These results implicate changes in neuropeptide expression in the SCN which may underlie the altered circadian responses to light in these animals.
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影响因子：
2.5
作者：
Itri, J;Colwell, CS
通讯作者：
Colwell, CS
影响因子：
56.9
作者：
Hattar, S;Liao, HW;Yau, KW
通讯作者：
Yau, KW
影响因子：
2.5
作者：
COLWELL, CS;FOSTER, RG
通讯作者：
FOSTER, RG
DOI：
10.1007/bf00198171
发表时间：
1991-01-01
期刊：
JOURNAL OF COMPARATIVE PHYSIOLOGY A-SENSORY NEURAL AND BEHAVIORAL PHYSIOLOGY
影响因子：
--
作者：
FOSTER, RG;PROVENCIO, I;MENAKER, M
通讯作者：
MENAKER, M
影响因子：
4.2
作者：
Kawamoto, K;Nagano, M;Okamura, H
通讯作者：
Okamura, H