Paspalas Constantinos, Consoulas Christos, Theophilidis George
Laboratory of Animal Physiology, Department of Zoology, School of Biology, University of Thessaloniki, GR-54006, Thessaloniki, Macedonia, Greece.
Rouxs Arch Dev Biol. 1993 Apr;202(4):204-213. doi: 10.1007/BF02427881.
The anatomy and innervation of the lateral external muscle and sensory cells located in the ventral region of pregenital abdominal segments were examined at the larval and adult stages ofTenebrio molitor (Coleoptera). All seven muscles located in this region degenerate during the pupal stage, whilst only the lateral external median (lem) appears in the adult. Backfillings of the motor nerve innervating this muscle reveal that, at both larval and adult stages, it is innervated by ten neurons. Intracellular records from the muscle fibres show that two neurons are inhibitory, and at least five are excitatory. There are also two unpaired neurons. A variety of sensory organs are located in the ventral region of the larvae, whilst only campaniform sensilla are found in the adult. At both stages, the innervation pattern of the sensory nerve branches is very similar. Also, the central projections of the sensory cells occupy similar neuropilar areas. Finally, prolonged intracellular records from the lem muscle revealed that, at the larval stage, it participates only in segmental or intersegmental reflexes, whilst in the adult it has a primary expiratory role in ventilation. The results show that extensive changes occur in the number of muscles located in the ventral region of the pregenital abdominal segments, as well as in the arrangement and number of sensory neurons, in the structure of the exoskeleton, and even in the central nervous system. In contrast, only minor changes are observed in the sensory and motor nerve branches, in the sensory projections, and in the number and the location of the motoneurons innervating the lateral external median muscle.
在黄粉虫（鞘翅目）的幼虫和成虫阶段，对位于生殖前腹部节段腹侧区域的外侧外肌和感觉细胞的解剖结构及神经支配进行了研究。该区域的所有七块肌肉在蛹期退化，而在成虫中仅出现外侧外中间肌（lem）。对支配该肌肉的运动神经进行逆向填充显示，在幼虫和成虫阶段，它均由10个神经元支配。对肌纤维的细胞内记录表明，其中两个神经元是抑制性的，至少五个是兴奋性的。此外还有两个不成对的神经元。幼虫的腹侧区域有多种感觉器官，而成虫中仅发现钟形感器。在两个阶段，感觉神经分支的神经支配模式非常相似。而且，感觉细胞的中枢投射占据相似的神经毡区域。最后，对lem肌肉进行的长时间细胞内记录显示，在幼虫阶段，它仅参与节段性或节间反射，而在成虫中它在呼吸过程中起主要呼气作用。结果表明，在生殖前腹部节段腹侧区域的肌肉数量、感觉神经元的排列和数量、外骨骼结构甚至中枢神经系统中都发生了广泛变化。相比之下，在感觉和运动神经分支、感觉投射以及支配外侧外中间肌的运动神经元的数量和位置方面，仅观察到微小变化。
