Subjects and housing
Animals were housed in a temperature-controlled animal room (22 +/- 2 °C) on a 12 h light/dark cycle (light on from 07:00 to 19:00), with artificial light (60-70 lumens). Food and water were available ad libitum.
RVI test requires a resident subject and an intruder. Residents were Sprague-Dawley male rats of 60 days and 350 g (average weight). Intruders were Sprague-Dawley male rats of 50 days and 280 g (average weight). Resident subjects were divided into 2 groups (n=10). Experimental subjects were injected with pCPA and returned to their home cage for 6 days; control subjects were injected with a vehicle and returned to their home cage, at the same time. After the RVI test residents were euthanized and OB were removed for posterior analysis (Koolhaas et al., 2013). Intruder subjects remained housed in groups of 3 until the test and they were euthanized after it.