This behavioral task is conducted by first placing the subject in the brightly-illuminated white compartment facing the sliding  guillotine door. After the subject turns in the opposite direction, the door is lowered into the floor allowing free access to the darker compartment of the apparatus. When the subject rotates again and faces the open door, a timer is started and the latency to completely enter the dark compartment is recorded. Upon entering the dark compartment, the sliding door is raised and a footshockis administered (from 0.35 to 0.45 mA, for 0.5 or 1 second). Immediately after the footshock training, the subject is removed from the apparatus and administered a pharmacological treatment either systemically or directly into a specific brain structure. 

Memory for the footshock training is assessed by a retention test administered from 24 to 96 hours later. In this test, the subjects are placed in the illuminated compartment as before, the door is lowered and the latency to enter the dark compartment where footshock was received earlier (maximum 600 s) is recorded and used as the index of retention.