[Mechanism of temperature sensitivity of ampulla of Lorenzini electroreceptors]

In acute experiments on the Black sea skates (Raja clavata) the transepithelial potential of Lorenzinian ampullae and impulse activity of their single nerve fibres were studied during electrical and thermal stimulation. The potential inside the canal and input resistance of the ampulla were 0 divided by -2 mV and 250-400 k omega respectively. Heating of the capsule was accompanied by a negative wave of the potential, an increase in the ampulla resistance and a decrease in spike frequency. Cooling of the preparation caused the opposite changes in the parameters. Waves of the transepithelial potential are supposed to reflect changes in the potential difference across the basal membrane of a receptor cell, which is hyperpolarized by heating.