Murakami D M, Fuller C A
Department of Animal Physiology, University of California, Davis.
Brain Behav Evol. 1990;35(5):302-12. doi: 10.1159/000115876.
This study compared the patterns of retinal projections and oxidative metabolism in the hypothalamus of squirrel monkeys, Bonnet macaques, and tree shrews. Intraocular injections of horseradish peroxidase in primates demonstrated that retinal terminals were present from the anterior to posterior poles of the suprachiasmatic nucleus (SCN). The terminals were primarily located in the ventral and ventrolateral regions of the SCN. In addition, there was a relatively even density and distribution of retinal terminals between the ipsilateral and contralateral projections. The pattern of oxidative metabolism in the hypothalamus of the primates examined demonstrated that the SCN is highly metabolic relative to the surrounding area, and distinct regions of the SCN exhibit clear differences in metabolism. These distinct metabolic regions may reflect functional subdivisions within the SCN. In addition, elevated metabolism is found along the hypothalamo-optic chiasm border. The retinal projection to the hypothalamus in tree shrews was very different from that of the primates examined. The contralateral retinal projection was very dense, but the ipsilateral retinal projection was very sparse. Retinal terminals were primarily distributed along the lateral border of the SCN. Both the SCN and the region lateral to the SCN exhibited elevated oxidative metabolism relative to the surrounding hypothalamus.
本研究比较了松鼠猴、冠毛猕猴和树鼩下丘脑的视网膜投射模式和氧化代谢情况。在灵长类动物中，眼内注射辣根过氧化物酶显示，视网膜终末存在于视交叉上核（SCN）从前极到后极的区域。这些终末主要位于SCN的腹侧和腹外侧区域。此外，同侧和对侧投射之间视网膜终末的密度和分布相对均匀。所检查的灵长类动物下丘脑的氧化代谢模式表明，相对于周围区域，SCN的代谢活性很高，并且SCN的不同区域在代谢方面表现出明显差异。这些不同的代谢区域可能反映了SCN内的功能细分。此外，在下丘脑-视交叉边界沿线发现代谢增强。树鼩视网膜向下丘脑的投射与所检查的灵长类动物非常不同。对侧视网膜投射非常密集，但同侧视网膜投射非常稀疏。视网膜终末主要分布在SCN的外侧边界沿线。相对于周围下丘脑，SCN及其外侧区域均表现出氧化代谢增强。
