2.4.7. Discriminated Avoidance

Using a T-maze apparatus set on a grid floor set to deliver 0.69 mA scrambled shock, we tested the mice for learning and cognitive flexibility using a discriminated avoidance task. During the information trial (first one), a shock is administered when the mouse enters their preference arm (first one) and allowed to escape the shock by running to the opposite arm (correct arm). Thereafter, the initiation of shock was 5 s upon start door opening or upon entry into an incorrect arm until the mouse entered the correct arm or a maximum of 60 s. After 10 s in the correct arm, the mouse was placed in a holding cage for 1 min (ITI). Training continued until a criterion of correct avoidance was reached (choosing the correct arm in under 5 s in four out of five trials, with the last two being correct avoidances). The reversal sessions followed the same training and switching of the correct arm. Learning ability was considered inversely proportional to the number of trials required to reach the avoidance criterion.
