Schematic representation of experimental protocols and timelines. (A) Separate cohorts of CRFR2-null and control mice were tested for anxiety-like behaviour in the light/dark transfer and open-field tests: under basal conditions; immediately following ARS; following CVMS and again 24 to 48 h after an ARS applied 3 weeks after the end of CVMS; 24 to 48 h following ARS. (B) CRFR2-null and control mice were exposed to no stress, ARS or CVMS, and mRNA expression of stress-related genes and serotonin transporter (SERT) binding were quantified 12 h after the end of stress. 5-HT/5HIAA content in brain nuclei were quantified in unstressed mice and 24 h after ARS. (C) LCMRglu was measured in CRFR2-null and control mice one hour after administration of saline or 5-HTR agonist. (D) CRFR2 mRNA levels in brain were quantified over a 48-h time course following ARS or 7 days after CVMS in control mice. , ARS; , CVMS; d, days; w, weeks.