Electrophysiological responses to thermal stimuli in peripheral nerves of the African giant snail, Archachatina marginata S.

Abstract

In Archachatina marginata S. the activity of 264 single units of the lip nerves and the tentacle nerve was recorded during thermal stimulation of the lip region. 17.8% of all fibres responded with an increase in neuronal activity to temperature changes in the range from 12 to 36°C. The amount of fibres responding to peripheral warm or cold stimuli varied between the investigated nerves. In the tentacle nerve (N. olfactorius) 30.5% of the neurons responded either to peripheral warming or cooling. In the three lip nerves N. labialis internus, N. labialis externus, and N. labialis medianus 20, 17, and 9.5%, respectively, proved to be thermoresponsive. Additional behavioural tests revealed that the thermopreferendum of Archachatina marginata S. is in the broad range between 13 and 32°C.