Light-Dark Box Exploration Assay

In the last three days of the experiment, the animals underwent a light-dark box test (LDB). The light dark-box test was carried out according to the procedure described by Chocyk et al. [32 (link)] and Chamera et al. [33 (link)] in an apparatus consisting of a cage divided into two sections of equal size (one chamber was brightly illuminated by diodes (100 lux), whereas the other chamber was dark) by a partition with a door (10.6 cm × 10.4 cm). The apparatus was controlled with a computer system (TSE Systems, Bad Homburg, Germany). The whole experiment was carried out in a dark room, and the rats were kept in darkness for an hour before the test. At the beginning of each test session, the animal was placed in one corner of the light compartment, facing away from the gate. Then, the animal was allowed to move freely between the two chambers with the door open for 10 min. The behavioral response of rats during the trials was recorded by Fear Conditioning Software (TSE, Bad Homburg, Germany). The time spent in each compartment was recorded for each animal. After each trial, the chambers were cleaned to prevent bias based on olfactory cues.