Figure 2.
Rhythmic GPR stimulation elicits the gastric mill rhythm. Extracellular recordings of STG nerves were used to monitor the pyloric (mvn) and gastric mill rhythms (lgn, dgn, mvn). A, Left, Before rhythmic GPR stimulation, there was no gastric mill rhythm, but there was a weak pyloric rhythm. A, Right, During rhythmic GPR stimulation (black bars), a gastric mill rhythm was elicited, as is evident from the rhythmic alternating bursting in the DG and LG/GM neurons and the gastric mill-timed inhibition of the IC and VD neurons. Note that this gastric mill rhythm was entrained to the GPR stimulations. In both panels, the tonically active unit (dgn) represents the activity of the AGR neuron, a muscle tendon proprioceptor neuron that fires tonically in the isolated STNS (Combes et al., 1995). B, Rhythmic GPR stimulation elicited, but did not entrain, the gastric mill rhythm. A and B are from different preparations.