Sustaining olfaction at low salinities: evidence for a paracellular route of ion movement from the hemolymph to the sensillar lymph in the olfactory sensilla of the blue crab Callinectes sapidus.
Sustaining olfaction at low salinities: evidence for a paracellular route of ion movement from the hemolymph to the sensillar lymph in the olfactory sensilla of the blue crab Callinectes sapidus.
复制标题
在低盐度下维持嗅觉：蓝蟹 Callinectes sapidus 嗅觉感受器中从血淋巴到感器淋巴的离子运动的细胞旁途径的证据。
DOI：
10.1007/s004410000246
复制
发表时间：
2000
影响因子：
3.6
通讯作者：
Smith,PJ
中科院分区：
文献类型：
--
作者：
Gleeson,RA;McDowell,LM;Aldrich,HC;Hammar,K;Smith,PJ
先前报道的证据表明，在低盐度条件下，蓝蟹嗅觉树突的完整性是由审美细胞内扩散产生的离子微环境维持的。建议将离子从血淋巴扩散到感器淋巴来维持这种微环境。在这项研究中，使用镧作为细胞外液空间的电子致密标记，我们找到了血淋巴和感器淋巴之间的细胞旁连续性的形态学证据。当触角被灌注或用含有硝酸镧的溶液进行外部沐浴时，镧会渗透到美学内的细胞外液体空间。在淡水和海水适应的动物中都发现了这一点。使用自参考离子选择性微电极获得了来自美学的离子扩散的证据。 Ca2+ 和 K+ 都表现出与低盐度条件下的审美簇相关的向外定向的通量梯度。这些发现与离子从血淋巴扩散到感器淋巴在低盐度下的美学内产生离子/渗透微环境的概念是一致的。
Evidence reported previously suggests that in low-salinity conditions the integrity of the olfactory dendrites of the blue crab is sustained by a diffusion-generated ionic microenvironment within the aesthetascs. Diffusion of ions from the hemolymph to the sensillar lymph is proposed to maintain this microenvironment. In this study, using lanthanum as an electron-dense marker of extracellular fluid space, we find morphological evidence for paracellular continuity between the hemolymph and the sensillar lymph. Lanthanum penetrates extracellular fluid spaces within the aesthetascs when antennules are either perfused or bathed externally with solutions containing lanthanum nitrate. This was found in both freshwater- and seawater-acclimated animals. Evidence for ion diffusion from the aesthetascs was obtained using self-referencing, ion-selective microelectrodes. Both Ca2+and K+exhibit outwardly directed flux gradients associated with the aesthetasc tuft in low-salinity conditions. These findings are consistent with the concept that ion diffusion from the hemolymph to the sensillar lymph generates an ionic/osmotic microenvironment within the aesthetascs at low salinities.