Ferrari C C, Aldana Marcos H J, Carmanchahi P D, Affanni J M
Instituto de Neurociencia (INEUCI-CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires, Argentina.
Anat Rec. 1998 Nov;252(3):325-39. doi: 10.1002/(SICI)1097-0185(199811)252:3<325::AID-AR1>3.0.CO;2-T.
The sense of olfaction in armadillos plays an important role, suggested by the great development of the nasal structures, olfactory bulbs, and related brain regions. The mammalian olfactory mucosa is a privileged site of neuronal death and regeneration during the whole life span. A detailed knowledge of its ultrastructure is convenient for gaining insight into the factors controlling those phenomena. We performed this work in species not previously studied in order to provide a firm basis for further research on those factors. No information is available on the histology and ultrastructure of the olfactory mucosa in the order Xenarthra to which armadillos belong. Samples from the endoturbinals of the armadillo Chaetophractus villosus were prepared for light and electron microscopic examination by the usual conventional means. The olfactory epithelium of Chaetophractus villosus shows the classical three types of cells: supporting cells, olfactory receptor neurons, and basal cells. The olfactory neurons and the basal cells were similar to that described in other species. Two different types of supporting cells are described. An outstanding characteristic of the supporting cells is the normal presence of abundant phagosomes, apical secretory granules, apocrine-like protrusions, and highly developed smooth endoplasmic reticulum. Apoptotic bodies are frequently found in the infranuclear cytoplasm of supporting cells. The ductular epithelium of Bowman's glands reveals secretory activity. The lamina propria shows mixed Bowman's glands. Great development of smooth endoplasmic reticulum is observed in the mucous acinar cells. Evidence for merocrine and apocrine mechanisms in the Bowman's glands is presented. The presence of apoptotic bodies and phagosomes in supporting cells suggests a participation in the cellular events induced by cell death and proliferation of the olfactory epithelium. The variety of characteristics exhibited by the supporting cells of the olfactory mucosa may contribute to a deeper understanding of their scarcely known functions.
犰狳的嗅觉起着重要作用，这一点从鼻结构、嗅球及相关脑区的高度发育可以看出。哺乳动物的嗅觉黏膜在整个生命周期中是神经元死亡和再生的特殊部位。详细了解其超微结构有助于深入了解控制这些现象的因素。我们在之前未被研究过的物种中开展这项工作，以便为进一步研究这些因素提供坚实基础。关于犰狳所属的贫齿目动物嗅觉黏膜的组织学和超微结构尚无相关信息。通过常规方法制备了长毛犰狳内鼻甲的样本用于光镜和电镜检查。长毛犰狳的嗅觉上皮呈现出经典的三种细胞类型：支持细胞、嗅觉受体神经元和基底细胞。嗅觉神经元和基底细胞与其他物种中描述的相似。文中描述了两种不同类型的支持细胞。支持细胞的一个显著特征是通常存在丰富的吞噬体、顶端分泌颗粒、顶浆分泌样突起以及高度发达的滑面内质网。凋亡小体经常出现在支持细胞的核下细胞质中。鲍曼腺的导管上皮显示出分泌活性。固有层可见混合性的鲍曼腺。在黏液腺泡细胞中观察到滑面内质网高度发达。文中提供了鲍曼腺中局部分泌和顶浆分泌机制的证据。支持细胞中凋亡小体和吞噬体的存在表明其参与了嗅觉上皮细胞死亡和增殖所引发的细胞事件。嗅觉黏膜支持细胞所展现出的多种特征可能有助于更深入地理解其鲜为人知的功能。
