2.8. Novel Object Recognition (NOR) test
On the twenty fourth days after FeCl3 injection, NOR
test was performed to assess the effects of Fer-1 on the short-term
recognition memory of mice according to the previous investigation
(Lueptow, 2017). Briefly, in the habituation phase, mice were placed in
a polyvinyl chloride chamber (45 cm × 45 cm × 45 cm) for
familiarization. On the next day, mice were allowed to freely explore
the arena with two identical objects in the center for 10 min.
Twenty-four hours following the training trial, animals were placed in
the chamber in which one of the objects was replaced with a novel object
with different color and shape. Mice were allowed for 10 min exploratory
trial. The exploration time, which meant that the time when the mice
explored the familiar or novel object, was recorded in the NOR test. The
apparatus and objects were cleaned thoroughly with 75% ethanol solution
prior to each trial. The behavioral traits of each mouse were recorded
by a video tracking system. The time exploring novel object (N) and
exploring familiar object (F) were recorded carefully. The
discrimination index was analyzed using the following formula:
(N-F)/(N+F) ×100%.