Coordination of the activity of monoaminergic pedal neurons in fresh water snails

In fresh water pulmonate snails, contact with the water surface as well as a tactile stimulation of the mantle wall induces a co-ordinated activity in symmetrical pedal neurones RPeD1 and LPeD1. The GDC and GSC being not primary sensory neurones, their activity is co-ordinated by polysynaptic mechanisms. In both species, a depolarising current applied to the GDC and GSC caused a discharge in one of the columellar nerves. The data obtained suggest that the co-ordination of activity in the GDC and GSC may have a functional significance for controlling the left and right halves of the columellar muscle in respiration.