Crespo Carlos, Blasco-Ibáñez José Miguel, Marqués-Marí Ana Isabel, Alonso José Ramón, Briñón Jesús G, Martínez-Guijarro Francisco José
Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Valencia. C/Dr Moliner 50, E-46100 Burjasot, Spain.
J Chem Neuroanat. 2002 Jun;24(1):49-63. doi: 10.1016/s0891-0618(02)00018-2.
The distribution of vasoactive intestinal polypeptide (VIP)-immunopositive elements was analyzed in the olfactory bulb (OB) of the Western European hedgehog (Erinaceus europaeus) under light and electron microscopy. The immunoreactivity appeared in an abundant population of periglomerular cells of the glomerular layer, in interneurons of the external plexiform layer, and in a restricted group of deep short-axon cells of the internal plexiform layer, the granule cell layer and the white matter. In the glomerular layer, VIP-containing periglomerular cells constituted a population of non-GABAergic neurons and did not receive synapses from olfactory axons. In the EPL, VIP-immunoreactivity appeared in a morphologically heterogeneous population of GABAergic interneurons, most of them identified as satellite cells and Van Gehuchten cells. These interneurons exerted an abundant and selective innervation of the somata, primary and secondary dendrites of the principal mitral and tufted cells, but did not contact granule cells. Perisomatic innervation of the principal cells followed two different patterns. The first included 'normal' basket-like arrangements of VIP-containing varicosities surrounding the somata of mitral and tufted cells. In the second, a set of satellite cells gave rise to short dendritic shafts that embraced the somata of principal cells in an 'exuberant' basket-like arrangement. These two morphological patterns of perisomatic innervation of principal cells were correlated with a neurochemical specificity of the target. In this sense, the 'exuberant' basket-like structures were always found surrounding a subpopulation of principal cells that did not contain the calcium-binding protein parvalbumin (PV). By contrast, they were never found surrounding the subpopulation of PV-containing principal cells, which only showed 'normal' basket-like structures. This study provides new data on the connectivity and neurochemical features of the hedgehog olfactory bulb and suggests that the olfactory circuits in this species are more complex than those described in other mammals.
在光镜和电镜下分析了西欧刺猬（Erinaceus europaeus）嗅球（OB）中血管活性肠肽（VIP）免疫阳性元件的分布。免疫反应出现在肾小球层的大量球周细胞、外丛状层的中间神经元以及内丛状层、颗粒细胞层和白质中一组有限的深短轴突细胞中。在肾小球层，含VIP的球周细胞构成了一群非GABA能神经元，并且不接受来自嗅觉轴突的突触。在EPL中，VIP免疫反应出现在形态学上异质的GABA能中间神经元群体中，其中大多数被鉴定为卫星细胞和范·格胡滕细胞。这些中间神经元对主要的二尖瓣细胞和簇状细胞的胞体、初级和次级树突进行了丰富且选择性的支配，但不与颗粒细胞接触。主要细胞的胞体周围支配遵循两种不同的模式。第一种包括围绕二尖瓣细胞和簇状细胞胞体的含VIP曲张体的“正常”篮状排列。第二种模式中，一组卫星细胞产生短的树突轴，以“旺盛”的篮状排列围绕主要细胞的胞体。主要细胞胞体周围支配的这两种形态学模式与靶标的神经化学特异性相关。从这个意义上说，“旺盛”的篮状结构总是围绕着一群不含钙结合蛋白小白蛋白（PV）的主要细胞。相比之下，它们从未在含PV的主要细胞亚群周围发现，这些含PV的主要细胞仅显示“正常”的篮状结构。这项研究提供了关于刺猬嗅球连接性和神经化学特征的新数据，并表明该物种的嗅觉回路比其他哺乳动物中描述的更为复杂。
