2.2.1 Novel Object Recognition Test (NORT)
A modification of NORT protocol was performed (Ennaceur and Delacour, 1988). In brief, mice were placed in a 90° two-arm (25 x 20 x 5 cm) black maze, with removable walls for easy cleaning and light intensity in mid-field was 30 lux. Before the memory, trials mice were habituated to the apparatus for 10 min for 3 days. On day 4, the animals were submitted to a 10 min acquisition trial, in which they were allowed to freely explore two identical objects located at the end of each arm (First trial-Familiarization). After 2h (for short-term memory evaluation) and 24h (for long-term memory evaluation) from the first trial, the mice were submitted to a 10 min retention trial, in which one of the two identical objects had been replaced by a novel one. The behaviour was recorded, and the time spent that the mice spent exploring the new object (TN) and the old one (TO) were measured manually. Exploration was defined as sniffing or touching the objects with nose and/or forepaws. The discrimination index (DI) was calculated as (TN-TO)/(TN+TO). To avoid object preference biases, objects were alternated. 70% EtOH was used to clean the arms and objects after each trial for the elimination of olfactory cues.