Fig. 7. Excitatory actions of cholinergic agonists on the isolated cardiac ganglion (CG). (A) Extracellular recording from the trunk in control (top trace) and during 10^–5 mol l^–1 pilocarpine perfusion (bottom trace). (B) Pilocarpine (Pilocarp.) significantly increased the burst frequency, duty cycle, number of spikes per burst and spike frequency in the burst (Student's t-test; N=8; ^*P<0.05; ^**P<0.01). (C) Same preparation shown in A during wash (top trace) and in the presence of 10^–5 mol l^–1 nicotine (bottom trace). (D) Nicotine significantly increased the duty cycle, number of spikes per burst and spike frequency in the burst (Student's t-test; N=8; ^*P<0.05; ^**P<0.01).