Fig. 7.
Bath application of histamine receptor antagonists (10−6 mol l−1 triprolidine and 10−5 mol l−1 ranitidine) to the commissural ganglia (CoGs) blocked the excitation of the oesophageal pattern that was seen following pyloric suppressor (PS) stimulation and focal application of 10−4 mol l−1 histamine in control saline. (A) Oesophageal activity, seen as bursting of the oesophageal dilator 1 (OD1) neuron, recorded in saline containing histamine (HA) antagonists resembled activity recorded in control saline (cf. Fig. 6A). (B) Stimulation of the PS neurons (4 s, 30 Hz) did not alter the oesophageal pattern. (C) Focal application of histamine likewise had no effect on the oesophageal pattern in the presence of the histamine antagonists. All recordings are from the preparation shown in Fig. 6.