[The changes of integrated water response waves of frog tongues by divalent cations (Ca++, Mg++, Ba++, etc.)]

In the frog tongue, there is an interesting physiological phenomenon named water response. Accordingly, it is said that the frog gustatory nerve contains water fiber. In spite of much experimental data, the nature or establishing process of water response is now not yet clear. As a common process the enhancement effect of Ca++ on the water response is well known. Standing on this idea, the authors have comparatively investigated the effects of Ca++, Mg++, Ba++, and Sr++ which are all divalent ions on the integrated wave form of water response. Original water response (integrated wave form) was simply enhanced in height and width by Ca++. The effect of Sr++ was qualitatively and quantitatively very similar to the effect of Ca++. Mg++ suppressed the water response especially in the beginning phase. Ba++ first suppressed the height of water response but, after repetition of experimental procedure, sufficient size of water response was achieved. As far as the effect on the water response form, some are similar but some are different. It is conclusively supposed that the conditions which permit the release or removal of the tissue Ca++ are the conditions which render the water response larger, and vice versa.