Neural control of ventilation in the shore crab,Cardnus maenas

Summary1.Intracellular recordings were obtained from the scaphognathite motor neurons ofCarcinus maenas in an isolated ganglion preparation. The ability of intracellular current injection to perturb the ventilatory motor pattern was investigated.2.Intracellular injection of current pulses and steady current into all motor neurons penetrated could perturb the ventilatory rhythm. The observed effects included resetting of the ventilatory rhythm (Figs. 2, 4 and 6), starting and stopping the motor pattern (Fig. 5) and increasing or decreasing the frequency of the rhythm (Table 1).3.The resetting effect is not dependent upon the production of action potentials in the motor neurons (Figs. 2, 3).