Sites of L-glutamic acid (Glut) injection in the pons (P2‒P4) and medulla (P8‒P14). 0.2 M/0.5 μl of Glut injection in the brainstem produced either cardiovascular change (≥5%) or no effect (<5%). The symbols in the left and right side represent cardiac and blood pressure responses to Glut, respectively. The open and closed symbols represent increase and decrease of cardiovascular variables, respectively. For details see text. •: <5%, ●,○: ≥5%; ★,☆: ≥15%; ▲,△: ≥25%; ◼,◻: ≥35%; ◆,◇: ≥45%; 4V: fourth ventricle; 7: facial nucleus; BC: brachium conjunctivum; CNF: nucleus cuneiformis; IC: nucleus inferior colliculus; IO: inferior olive; LC: nucleus locus coeruleus; MLB: medial longitudinal bundle; NGC: nucleus gigantocellularis; NMC: nucleus magnocellularis; NPM: nucleus paramedianus; PT: pyramidal tract; SO: superior olive.