2.9 Open field test
Spontaneous locomotor activity of experimental C57BL/6J mice was studied
in the open field paradigm over a 5-min period(Zhi, Jin, Pan, Zhang, &
Liu, 2019), and separate groups of animals were used for this test. The
open field was divided into two areas, a peripheral area and a square
center. C57BL/6J mice were individually placed in the central of a
wooden box (height 40 cm, width 100 cm, length 100 cm). The test room
was illuminated with a red bulb (50 W) on the ceiling dimly. For open
field observations, the animals were placed in the central sector 30
minutes after a single injection. The computer software (EthoVision;
Noldus) calculated the velocity of movement, the distance of traveling,
and the time spent in the center of the open field. For each group, the
mean value and SEM was calculated. These parameters are thought to
reflect locomotor activity and fear or anxiety, respectively. The open
field apparatus was thoroughly cleaned between each trial.