Abstract
The S.M. GIX recorded from the nerve bundles of the isolated GIX of females in Bombyx mori changes the discharging activity by copulation. To analyze the mechanisms underlying the phenomenon, effects of various concentrations of Na+ and K+ in the extraganglionic fluid on the S.M. GIX-activity were examined and compared between virgin and copulated females. In standard Ringer's solution the S.M. GIX-activity of the copulated female was higher than that of the virgin female. In the 1mM and 10mM Na+ added Ringer's solution the S.M. GIX-activity of the copulated female was exceedingly higher than that of the virgin female. In the 1mM and 10mM K+ added Ringer's solution the S.M.G IX-activity of the virgin female was higher than that of the copulated female. According to the results, it was concluded that copulation seemed to change certain humoral conditions in the female. It was also postulated that the change of certain humoral conditions brought about by copulation had its effect on the selective permiability of Na+ and K+ by the nerve sheath surrounding the nervous system. This causes the Na/K ratio of the extra-neuronal fluid in the GIX to be changed from its ratio before copulation, and therefore, it may be understood that the S.M. GIX-activity is changed by copulation.
