Seress L, Abrahám H, Dóczi T, Lázár G, Kozicz T
Central Electron Microscopic Laboratory, Faculty of Medicine, University of Pécs, 7643 Pécs, Szigeti u. 12, Hungary.
Neuroscience. 2004;125(1):13-24. doi: 10.1016/j.neuroscience.2003.12.035.
Cocaine- and amphetamine-regulated transcript (CART) peptide immunocytochemistry was used to reveal cellular localization in the dentate gyrus and in Ammon's horn of the rat and human hippocampal formations. In the rat dentate gyrus, only granule cells were labeled, whereas in humans, only mossy cells of the hilar region expressed CART peptide immunoreactivity. In the rat, CART-positive granule cells were located at the molecular layer border of the granule cell layer and had no features that would distinguish them from other granule cells. The mossy fiber bundle was labeled in the hilus as well as along the entire CA3 area of Ammon's horn. In the human, CART-immunoreactive mossy cells displayed the characteristic thorny excrescences both on their somata and their main dendrites. Axon collaterals of mossy cells could be seen in the hilus and the main axons formed a dense band in the inner molecular layer of the dentate gyrus, suggesting that mossy cells are the principal source of the associational pathway. Granule cells of the dentate gyrus and pyramidal neurons of the human hippocampal formation were devoid of CART peptide immunoreactivity. A few labeled non-pyramidal cells and a large group of strongly immunostained axons of unknown origin were present in all layers of CA1-3. Granule cells are the main excitatory cell population of the dentate gyrus while mossy cells are in a key position in controlling activity of granule cells. The specific location of CART peptide in the dentate granule cells of rodents and in the mossy cells of the human hippocampus may indicate involvement of neuronal circuitry of the dentate gyrus in the memory-related effects of cocaine and amphetamine. Independently of its functional role, CART peptide can be used as a specific marker of human mossy cells and of the dentate associational pathway. The sensitivity of CART peptide to postmortem autolysis may restrict the use of this marker in surgically removed hippocampi or in human brains removed and fixed shortly after death.
采用可卡因和苯丙胺调节转录物（CART）肽免疫细胞化学方法，揭示大鼠和人类海马结构齿状回及海马角中CART肽的细胞定位。在大鼠齿状回中，仅颗粒细胞被标记，而在人类中，仅门区的苔藓细胞表达CART肽免疫反应性。在大鼠中，CART阳性颗粒细胞位于颗粒细胞层的分子层边界，没有可将它们与其他颗粒细胞区分开的特征。苔藓纤维束在门区以及海马角的整个CA3区域均被标记。在人类中，CART免疫反应性苔藓细胞在其胞体和主要树突上均显示出特征性的棘状突起。苔藓细胞的轴突侧支可见于门区，其主要轴突在齿状回的内分子层形成一条密集带，提示苔藓细胞是联合通路的主要来源。人类海马结构的齿状回颗粒细胞和锥体细胞缺乏CART肽免疫反应性。在CA1 - 3的所有层中均存在少数标记的非锥体细胞和一大群来源不明的强免疫染色轴突。颗粒细胞是齿状回的主要兴奋性细胞群体，而苔藓细胞在控制颗粒细胞的活动中处于关键位置。CART肽在啮齿动物齿状颗粒细胞和人类海马苔藓细胞中的特定定位可能表明齿状回的神经回路参与了可卡因和苯丙胺的记忆相关效应。独立于其功能作用，CART肽可作为人类苔藓细胞和齿状联合通路的特异性标记物。CART肽对死后自溶的敏感性可能会限制该标记物在手术切除的海马体或死后不久取出并固定的人脑中的应用。
