Open field test

The open field test (OFT) was performed as described to measure locomotor activity [31]. The open field apparatus consisted of a square arena (40×40 cm) with 30 cm high walls that was illuminated using an electric bulb hanging 2.5 m above the floor. Open field behaviors of the mice were recorded and analyzed using the ANY-maze system (Stoelting, Wood Dale, IL). Animals were exposed to the open field for 10 minutes. Between subjects, the box was thoroughly cleaned with 70% ethanol and the ethanol was allowed to evaporate completely prior to testing mice.