Keil T A, Steinbrecht R A
Max-Planck-Institut für Verhaltensphysiologie, Seewiesen, Federal Republic of Germany.
Tissue Cell. 1987;19(1):119-34. doi: 10.1016/0040-8166(87)90063-2.
The distribution of diffusion barriers in silkmoth olfactory sensilla has been investigated with ionic lanthanum. The tracer was applied from the apical side of the sensory epithelium by first pinching off the hair tips and then dipping the antennal branches into the La(NO(3))(3) solution. The tracer neither passed the apical septate junctions between the dendrite and the thecogen cell nor those between thecogen, trichogen, and tormogen cells, nor the tight contact between the apical membrane of the tormogen cell and the cuticle. After perfusing the hemolymph space with La(NO(3))(3) solution, the tracer was found in the clefts between the thecogen, trichogen, tormogen, and epidermis cells, but not in those between the receptor cells and the thecogen cell, or between the axon and the glial envelope. Lanthanum neither entered the receptor-lymph space nor the subcuticular space. Therefore, (i) receptor-lymph space, subcuticular space, and hemolymph space are isolated from each other, and (ii) the cleft between thecogen and sensory cell is separated from the hemolymph as well as from the receptor-lymph spaces. Furthermore, the results indicate that pleated septate junctions form the diffusion barriers in silkmoth olfactory sensilla.
利用离子镧对家蚕嗅觉感受器中扩散屏障的分布进行了研究。通过先掐断毛尖端，然后将触角分支浸入硝酸镧（La(NO₃)₃）溶液中，从感觉上皮的顶端侧施加示踪剂。示踪剂既不通过树突与皮细胞之间的顶端分隔连接，也不通过皮细胞、毛原细胞和膜原细胞之间的分隔连接，也不通过膜原细胞顶端膜与角质层之间的紧密接触。在用硝酸镧溶液灌注血淋巴间隙后，在皮细胞、毛原细胞、膜原细胞和表皮细胞之间的裂隙中发现了示踪剂，但在受体细胞与皮细胞之间或轴突与神经胶质包膜之间的裂隙中未发现。镧既未进入受体淋巴间隙也未进入皮下间隙。因此，（i）受体淋巴间隙、皮下间隙和血淋巴间隙相互隔离，且（ii）皮细胞与感觉细胞之间的裂隙与血淋巴以及受体淋巴间隙均分隔开。此外，结果表明褶皱状分隔连接在家蚕嗅觉感受器中形成了扩散屏障。
