Abstract
The patterned burst activity of cardiac pacemaker ganglion cells in Homarus americanus has been studied by means of intracellular recording electrodes. Burst activity, highly similar to that seen in cells of intact ganglia, has been demonstrated in ganglion sections containing as few as two large-cell bodies. Studies of the sectioned preparations have shown that potential deflexions during the burst period are mainly endogenous activity of the respective cells and not post-synaptic potentials. The behaviour of the cells in the period between bursts suggests the action of an inhibitory conductance change in each of the cells during this period.