2.2.2 Morris Water Maze (MWM)
The MWM test was performed as described previously (Griñan-Ferré et al., 2016) in an open circular pool, filled with water which temperature was maintained at 22 °C ± 1. The water surface was divided into four quadrants (Q1, Q2, Q3, and Q4) by two principal perpendicular axes, and five starting points were set (1,2,3,4). Four visual clues were placed on the walls of the tank (1,2,3,4). The animals’ swimming paths were recorded, and the data were analysed with SMART version 3.0 software. On day 1, mice were placed individually into the pool, facing the wall, and allowed to swim for 60 seconds in order to be habituated to the experimental conditions. On day 2, a white platform was submerged 1.5 cm below the water level in the middle of the Q1 platform and the acquisition phase took place for 5 days. Each day the animals were submitted to five trials starting from the positions set in random order. At each trial mice were allowed to swim for 60 seconds and if not able find the platform within 60 seconds were guided to the visible platform. The mice remained for 30s onto the platform for spatial orientation. There was no resting phase between each trial and the subsequent one. 24h after the last training, a memory test was performed after the platform was removed from the pool in which the mice were tested for 60s. The distance to target, and the time spent in platform quadrant (Q1), among other parameters, were measured.