Figure 1.

Experimental timeline. Mice arrived at the facility on Day 0. On Day 1, mice were subjected to either unstressed or unpredictable chronic stress (UCS) conditions composed of scheduled but varying daily hassles. Following this two-week period of stress or no stress, all mice received a single injection (Day 14) of either vehicle (0.9% saline, i.p.) or 30 mg/kg ketamine. Thirty minutes after injection, tail vein blood was collected for corticosterone measurement. Twenty-four hours later (Day 15), mice were given an open field test (OFT), followed by an elevated zero maze (EZM) test on Day 16, and the forced swim test (FST) on Day 17.