2.3.4. Marble Burying Test (MB)

Mice were placed individually in a standard home cage containing nine glass marbles (dimensions 1 × <sup>1</sup> × 1 cm3) evenly spaced making a square (three rows of three marbles per row only in the left area of the cage) on a 5 cm thick layer of sawdust. The mice were left in the cage with marbles for a 30 min period after which the test was terminated by removing the mice and counting the number of marbles: intact (untouched), rotated (90 or 180◦), half-buried (at least <sup>1</sup> <sup>2</sup> buried by sawdust), and buried (completely hidden).
