Division of Brain Biology, National Institute for Basic Biology Okazaki, Japan ; Department of Basic Biology, Graduate University for Advanced Studies (SOKENDAI) Okazaki, Japan.
Front Neural Circuits. 2014 May 19;8:52. doi: 10.3389/fncir.2014.00052. eCollection 2014.
To better understand serotonin function in the primate brain, we examined the mRNA expression patterns of all the 13 members of the serotonin receptor (5HTR) family, by in situ hybridization (ISH) and the distribution of serotonergic terminations by serotonin transporter (SERT) protein immunohistochemical analysis. Ten of the 13 5HTRs showed significant mRNA expressions in the marmoset brain. Our study shows several new features of the organization of serotonergic systems in the marmoset brain. (1) The thalamus expressed only a limited number of receptor subtypes compared with the cortex, hippocampus, and other subcortical regions. (2) In the cortex, there are layer-selective and area-selective mRNA expressions of 5HTRs. (3) Highly localized mRNA expressions of 5HT1F and 5HT3A were observed. (4) There was a conspicuous overlap of the mRNA expressions of receptor subtypes known to have somatodendritic localization of receptor proteins with dense serotonergic terminations in the visual cortex, the central lateral (CL) nucleus of the thalamus, the presubiculum, and the medial mammillary nucleus of the hypothalamus. This suggests a high correlation between serotonin availability and receptor expression at these locations. (5) The 5HTRs show differences in mRNA expression pattern between the marmoset and mouse cortices whereas the patterns of both the species were much similar in the hippocampus. We discuss the possible roles of 5HTRs in the marmoset brain revealed by the analysis of their overall mRNA expression patterns.
为了更好地了解灵长类动物大脑中的血清素功能,我们通过原位杂交(ISH)和血清素转运蛋白(SERT)免疫组织化学分析来检查 13 种血清素受体(5HTR)家族成员的所有成员的 mRNA 表达模式。在狨猴脑中,有 13 种 5HTR 中有 10 种显示出显著的 mRNA 表达。我们的研究显示了狨猴脑中血清素系统组织的几个新特征。(1)与皮质、海马体和其他皮质下区域相比,丘脑仅表达有限数量的受体亚型。(2)在皮质中,5HTR 的表达具有层选择性和区域选择性。(3)观察到 5HT1F 和 5HT3A 的高度局部化 mRNA 表达。(4)在视觉皮层、丘脑中央外侧(CL)核、前下小叶和下丘脑乳头体中,已知具有 somatodendritic 定位受体蛋白的受体亚型的 mRNA 表达与密集的血清素终末之间存在明显的重叠。这表明在这些位置,血清素的可用性与受体表达之间存在高度相关性。(5)5HTR 在狨猴和小鼠皮质中的 mRNA 表达模式存在差异,而在海马体中,两种物种的模式都非常相似。我们讨论了通过分析其整体 mRNA 表达模式揭示的 5HTR 在狨猴脑中的可能作用。