Figure 1. Representative chart recordings showing the effect of microinjection of glutamate (4 nmol (20 nl)⁻¹) or PrRP (2 pmol (20 nl)⁻¹) into the rostal (A) and caudal (B) DMV on IGP and arterial blood pressure (BP).

A, microinjection of l-glutamate into the DMV at a level of the area postrema (0.3 mm rostral to the CS) evoked a transient increase in IGP, whereas administration of PrRP at the same site produced marked gastric contraction and evoked phasic increases in IGP (inset shows boxed region at expanded scale). B, administration of l-glutamate or PrRP into the caudal DMV at a level 0.1 mm posterior to the CS induced gastric relaxation, as evidenced by decreases in baseline IGP, and inhibited phasic contractions. Both types of gastric motor response to microinjection of PrRP occurred independently of changes in arterial pressure (A and B, lower traces).