Fig. 1. The photomicrograph (A ) shows injection sites (arrows ) and lesion regions (dashed-line circle ) on two sides of the rostral medial medulla (RMM) including DPGi and Gi in a rat receiving bilateral injections of ibotenic acid. The schematic diagram (B ) shows a summary of the injection sites (filled circles ) and the lesion regions (hatched area ) on a coronal section at the interaural level −2.0 mm from 13 animals receiving bilateral lesion treatments. The borderline of the hatched areas on both sides of the lower brain stem represent the maximal areas to where the lesions are confined. 4 V, 4th ventricle; DPGi, dorsal paragigantocellular nucleus; Gi, gigantocellular reticular nucleus; g7, genu of the facial nerve; Sp5, spinal nucleus of trigeminal nerve. Scale bar in A = 750 μm.