“…Transition metal ions, such as Ni 2+ , Co 2+ and Mn 2+ ions, at concentrations below 5 mM are barely effective in producing nerve impulses in the water fibers of the frog glossopharyngeal nerve (Kitada, 1990(Kitada, , 1994b. However, they have enhancing effects on the responses to Ca 2+ (Kitada, 1994b, c), Mg 2+ (Kashiwagura et ai, 1978;Kitada, 1994b) and Na + (Kashiwagura et al, 1978;Herness, 1987Herness, , 1991Kitada, 1994b) ions. Transition metal ions do not affect antagonism between Ca 2+ and Mg 2+ ions and between Ca 2+ and Na + ions in the neural responses to a mixture of two salts (Kitada, 1994b).…”