[Effect of calcium ions on the electrical and temperature sensitivity of the ampullae of Lorenzini of Black Sea skates].

Changes in the ambient calcium concentration affected similarly both thermal and electrical sensitivity of electroreceptors of the Lorenzini ampullae in the skates. In Ca-free solution containing EGTA the sensitivity first decreased, then increased and after that blocking of synaptic transmission occurred. In Ca-rich solution both thermal and electrical sensitivity decreased. Changes of spontaneous activity occurred much later than those of evoked responses.