Testing was conducted according to previously published protocols [43]. Mice were habituated to drinking water from two stoppers fitted with ball-point sipper 50-ml tubes for at least 1 week before testing. Mice were individually housed in the behavioral testing room 4 h before testing and then provided with a free choice between plain water and 1% sucrose during the first 2 h after lights were switched off in the dark cycle. The amount of water and sucrose consumed was evaluated by weight. The preference for sucrose solution was calculated by determining the percentage of total sucrose consumption volume divided by total liquid consumption volume (sucrose + water). For mice subjected to 3 days of subchronic unpredictable stress, the sucrose preference test was performed 24 h after the last stressor.
