Diagram showing the sites where the microinjections occurred. A, left: cartoon of a coronal slice. ▪ and ▴, Locations of the microinjections in the cMRR of 6 rats;×, 4 microinjections outside the cMRR in 2 rats. A, right: representative slice containing the cMRR. Areas stained by Chicago Sky Blue are circled. B and C: ▪, locations of the microinjections in the middle MRR (mMRR; B) and rostral MRR (rMRR; C), respectively. Amb, nucleus ambiguus; IRt, intermediate reticular nucleus; LPB, lateral parabrachial nucleus; ml, medial lemniscus; Mo5, motor 5 nucleus; NTS, nucleus of solitary tract; PCRtA, parvicellular reticular nucleus alpha; Pr5VL, ventrolateral part of principal sensory 5 nucleus; ROb, raphe obscurus nucleus; RMg, raphe magnus nucleus; RPa, raphe pallidus nucleus; RVL, rostroventrolateral reticular nucleus; 7, facial nucleus; Sp5I, interpolar part of spinal 5 nucleus; Sp5O, oral part of spinal 5 nucleus.