“…The brainstem sections were reconstructed using the corresponding Nissl-stained control sections and the stereotactic atlas of the rat brain (Paxinos and Watson, 1998) on an image analysis system (Neurolucida, MicroBrightField, Colchester, VT). Examined brainstem regions included the second-order sensory nuclei of laryngeal afferents, that is the NTS, spinal trigeminal nucleus (Sp5), and intermediate/parvicellular reticular formation (IRF/PCRF) (Altschuler et al, 1989; Patrickson et al, 1991; Travers and Norgren, 1995; Hayakawa et al, 2001); the laryngeal motor nucleus, that is the NA (Gacek, 1975; Yoshida et al, 1982); the higher-order nucleus of laryngeal control, that is the PAG (Ambalavanar et al, 1999); and the non-specific nuclei of the laryngeal control, that is the area postrema (AP) and locus coeruleus (LC) (Ambalavanar et al, 2004). Within the NTS, we examined its medial (NTSm), interstitial (NTSi), and intermediate (NTSim) subnuclei; within the PAG, we examined its lateral (LPAG), dorsomedial (DMPAG), dorsolateral (DLPAG) and ventrolateral (VLPAG) subnuclei.…”