Denizot J P, Kirschbaum F, Schugardt C, Bensouilah M
Institut Alfred Fessard/CNRS, Gif-sur-Yvette, France.
Neurosci Lett. 1998 Jan 30;241(2-3):103-6. doi: 10.1016/s0304-3940(98)00030-5.
The ontogeny of the electroreceptors of two species of mormyrids, Campylomormyrus cassaicus and Pollimyrus isidori, was studied. In young larvae (10 and 12 days old, respectively) ampullary organs, knollenorgans, promormyromasts and two types of tuberous organs (differing by their accessory cells) were found. These latter each possess a single sensory cell sitting on a platform of accessory cells. The platform is pierced by an unmyelinated nerve fibre. The promormyromast is composed of a single sensory cell surrounded by several accessory cells. The free apical area of the sensory cell and the accessory cells protrude into an intraepidermal cavity. The receptor cell is innervated by an unmyelinated nerve fibre ending in synaptic boutons. At the disappearance of the larval and appearance of the adult electric discharge the two types of tuberous organs degenerate, whereas the promormyromast differentiates into the typical mormyromast consisting of two types of sensory cells. The two types of tuberous organs and the promormyromast therefore are termed larval electroreceptors. Mormyrids are therefore the first group of electric fish possessing a complete larval electric system, comprising not only a larval electric organ, but also a larval electrosensory system.
对两种裸臀鱼科鱼类——卡氏曲臀鱼（Campylomormyrus cassaicus）和伊氏多鳍鱼（Pollimyrus isidori）的电感受器个体发育进行了研究。在幼体幼虫（分别为10日龄和12日龄）中，发现了壶腹器官、球囊器官、前莫氏乳突和两种类型的管状器官（因其辅助细胞不同而有差异）。后两种器官各自有一个位于辅助细胞平台上的单个感觉细胞。该平台被一条无髓神经纤维穿透。前莫氏乳突由单个被几个辅助细胞包围的感觉细胞组成。感觉细胞和辅助细胞的游离顶端区域突出到表皮内腔中。受体细胞由一条在突触小体处终止的无髓神经纤维支配。在幼虫消失和成年鱼放电出现时，两种类型的管状器官退化，而前莫氏乳突分化为典型的由两种类型感觉细胞组成的莫氏乳突。因此，这两种类型的管状器官和前莫氏乳突被称为幼虫电感受器。因此，裸臀鱼科鱼类是第一批拥有完整幼虫电系统的电鱼，该系统不仅包括幼虫电器官，还包括幼虫电感觉系统。
