Hornung J P, Fritschy J M, Törk I
Institute of Anatomy, Lausanne, Switzerland.
J Comp Neurol. 1990 Jul 8;297(2):165-81. doi: 10.1002/cne.902970202.
The serotoninergic innervation of the marmoset (New World monkey, Callithrix jacchus) cerebral cortex has been analyzed by using immunocytochemistry. The use of a sensitive monoclonal antibody against serotonin allowed the visualization of the fine morphology of individual axons. Two types of terminal axons were demonstrated: one has sparse, small, ovoid varicosities (dia. less than 1 micron), and the other has large, spheroidal varicosities (up to 5 microns in dia.), which are more densely clustered. The first type of axon is distributed through all cortical layers, with a characteristic laminar distribution that varies from area to area. The second type of axons was distributed sparsely in all regions but was markedly denser in the frontal and anterior parietal lobes, and in the hippocampal formation. Axons with large varicosities typically surrounded certain cell bodies and proximal dendrites, forming pericellular arrays, or baskets. These morphological specializations were most frequent in the frontal and anterior parietal cortex, where they were found around stellate and horizontal cells in layer I and around stellate and bipolar cells in layer II and III. Similar baskets were also found in the hippocampal formation, mainly along the border between the hilus and the granule cell layer of the dentate gyrus, across the CA4 field, and at each side of the pyramidal cell layer of the CA3 regions. The distribution and cellular morphology of the cell surrounded by the 5-HT basket fibres were suggestive of a subpopulation of interneurons, possibly GABAergic and/or peptidergic. In agreement with previous reports on the innervation of the cerebral cortex of other mammalian species, the marmoset cerebral cortex is innervated by two separate subsystems of serotoninergic axons. One of these may have a strong and specific influence on the cortical inhibitory circuitry, via relay through cortical interneurons.
通过免疫细胞化学方法，对狨猴（新大陆猴，绢毛猴）大脑皮质的5-羟色胺能神经支配进行了分析。使用一种针对5-羟色胺的敏感单克隆抗体，可观察到单个轴突的精细形态。研究显示出两种终末轴突：一种具有稀疏、小的卵形膨体（直径小于1微米），另一种具有大的球形膨体（直径可达5微米），且更为密集地聚集。第一种轴突分布于所有皮质层，具有因区域而异的特征性分层分布。第二种轴突稀疏地分布于所有区域，但在额叶和顶叶前部以及海马结构中明显更为密集。具有大膨体的轴突通常围绕某些细胞体和近端树突，形成细胞周围阵列或篮状结构。这些形态特化在额叶和顶叶前部皮质最为常见，在那里可在第I层的星状细胞和水平细胞周围以及第II和III层的星状细胞和双极细胞周围发现。在海马结构中也发现了类似的篮状结构，主要沿着齿状回的门区与颗粒细胞层之间的边界、穿过CA4区以及在CA3区锥体细胞层的两侧。被5-羟色胺篮状纤维围绕的细胞的分布和细胞形态提示为中间神经元亚群，可能是γ-氨基丁酸能和/或肽能的。与先前关于其他哺乳动物物种大脑皮质神经支配的报道一致，狨猴大脑皮质由两个独立的5-羟色胺能轴突子系统支配。其中一个子系统可能通过皮质中间神经元进行中继，对皮质抑制性回路产生强烈而特定的影响。
