“…The differentiating protocol involved plating PC12 and PC12-H 3 cells on tissue culture plates coated with collagen (rat tail type VII; SigmaAldrich, St. Louis, MO) combined with exposure to low serum medium containing 1% fetal bovine serum, 0.5% donor horse serum, 1% L-glutamine, and antibiotics supplemented with 7S-NGF (BD Biosciences Discovery Labware, Bedford, MA). For each experiment, the culture medium was aspirated and cells were washed twice with Na-Ringer's (140 mM NaCl, 5 mM KCl, 10 mM HEPES, 1 mM MgCl 2 , 2 mM glucose, and 2 mM CaCl 2 ), then incubated with BNP (100 nM), for 20 min in an incubator at 37°C either in the absence or presence of methimepip (histamine H 3 receptor agonist; 1 nM) (Kitbunnadaj et al, 2005), 4-methylhistamine (histamine H 4 receptor agonist; 20 M) (Lim et al, 2005), 1-{3-[4-(piperidin-1-ylmethyl)phenoxy]propyl}piperidine (JNJ5207852) (histamine H 3 receptor antagonist; 30 nM) (Barbier et al, 2004), or 4-((3R)-3-amino-pyrrolidin-1-yl)-6,7-dihydro-5H-benzo [6,7]cyclohepta[1,2-d]pyrimidin-2-ylamine (A943931) (histamine H 4 receptor antagonist; 300 nM) (Cowart et al, 2008). When these drugs were used, PC12-H 3 cells were preincubated with them for 10 min.…”