Fig. 7.

Selective action of Po₂ on gastropyloric interaction in vitro. A, During superfusion of the STG alone with equilibrated saline at Po₂ = 2.5 kPa, the spontaneously active gastric and pyloric networks express an interaction (arrows) similar to that seen in resting and unfed animals. Each onset of a gastric MG neuron burst (solid line above lvn trace) is followed by a single perturbation in the pyloric network cycle.B, Superfusing the STG with saline oxygenated at 5 kPa leads to a disappearance of the internetwork interaction, without affecting pyloric or gastric cycle frequency in this Po₂ range. C, This specific action is reversed on return to control conditions. τ_pyl, Pyloric cycle period.