McIver Susan, Siemicki Roman
Department of Zoology, University of Toronto, Toronto, Ontario, Canada M5S 1A1.
J Morphol. 1985 Jan;183(1):15-23. doi: 10.1002/jmor.1051830103.
At least five nonporous sensilla with inflexible sockets (npsensilla) occur on each antenna of both sexes of adult Rhodnius prolixus. Externally the sensillum appears as a short, rounded peg set into a pit surrounded by a depression. A very electron-dense material occurs in the peg lumen and the inner aspect of the pit. Filamentous extensions of this material radiate into the overlying outlets. Each sensillum is innervated by three neurons with unbranched dendrites. Two dendrites extend to the peg tip and distally are covered by a dendritic sheath. The portion of these dendrites within the sheath contains a large number of microtubules. The third dendrite terminates near the base of the dentritic sheath and partially wraps around the other two dendrites. Three sheath cells are associated with each sensillum. Based on similarities in structure with sensilla of known function it is probable that the np-sensilla of R. prolixus are thermo-/hygrosensilla responding to cold, dryness and wetness. The sensilla have a number of structural similarities with insect rectal sheath cells known to absorb atmospheric water by electroosmosis. Possibly this process leads to volumetric alterations of cuticular elements associated with the dendrites and ultimately to mechanotransduction.
成年南美锥蝽两性的每只触角上至少有五个具坚硬窝的无孔感器（npsensilla）。从外部看，感器呈现为一个短的、圆形的栓，置于一个被凹陷包围的坑中。在栓腔和坑的内侧出现一种电子密度非常高的物质。这种物质的丝状延伸辐射到上方的出口。每个感器由三个具有无分支树突的神经元支配。两个树突延伸到栓尖，远端被一个树突鞘覆盖。这些树突在鞘内的部分含有大量微管。第三个树突在树突鞘基部附近终止，并部分包裹另外两个树突。每个感器与三个鞘细胞相关联。基于与已知功能的感器在结构上的相似性，南美锥蝽的np-感器很可能是对寒冷、干燥和潮湿做出反应的温/湿感器。这些感器与已知通过电渗作用吸收大气水分的昆虫直肠鞘细胞在结构上有许多相似之处。可能这个过程导致与树突相关的表皮成分的体积变化，并最终导致机械转导。
