Fos cell counts (means ± SE) in the PBN, the CeA, and the BNSTv 6 and 48 h after intraperitoneal injection with saline or cisplatin (30 mg/kg), with or without palonosetron (a 5-HT3 receptor antagonist). *P < 0.05, LSD test, cisplatin or cisplatin + palonosetron compared with saline injection; aP < 0.05, LSD test, cisplatin vs. cisplatin + palonosetron.