Cyclic electrical activity in the intestine of marine nematode Enoplus brevis

摘要

In the nematode Caenorhabditis elegans the defecation motor program (DMP) is initiated by calcium concentration oscillations between intestinal cells without participation of the nervous system. In the related nematode Heterorhabditis megidis it was shown that DMP is accompanied by electrical membrane potential oscillations in the intestinal cells. Calcium oscillations and membrane potential in these species are cell-autonomous, and they are synchronised between cells through gap junctions. In the midgut cells of distant from Rhabditida nematode Enoplus brevis (Enoplida) we discovered membrane potential cycling which resemble oscillations in H. megidis. We also found that the gut cells in E. brevis are electrically connected through gap junctions. This finding indicates that distant nematode species possess the same non-nervous rhythmical generation DMP mechanism. It appears that this mechanism was present in the nematode last common ancestor.