1. The new burster has been localized in the middle of the visceral ganglion under the superficial layer of neurones. It fires trains of 1–13 spikes and receives IPSP's from an unidentified sensory or interneurone. 2. Steady-state I–V membrane characteristics show inward going anomalous rectification and hysteresis but the slope membrane resistance and anomalous rectification character change from time to time depending on the functional state. 3. Acetylcholine (5 × 10 −5M) increased the average spike frequency but hardly decreased the slope membrane resistance of this neurone. It could be characterized as a not very sensitive D- or DINHI-neurone. 4. Ba 2+ influenced the neuronal activity on two distinct ways. First of all it excited the neurone with a shorter time course and its excitatory effect strengthened if the Ca 2+ concentration in the medium was low. Ba 2+ inhibited the neuronal activity with a longer time course activating the inhibitory nerve terminals in a direct and/or indirect ways and this effect increased if the Ca 2+ concentration was elevated. 5. In the barium evoked inhibitory period the slope membrane resistance decreased, the hysteresis disappeared and linear I–V relation predominated.