2.11. Y-Maze Test

The Y-maze test was performed to evaluate the spatial memory or perception of the mice after scopolamine-induced neuronal injury. The Y-shaped maze having 5 : 20 : 10 of width : length : height was prepared, and the three arms of Y shape were allocated as A, B, and C. Mice were trained in the Y-maze before the start of the experiment. Mice were randomly divided into groups of saline, donepezil (2 mg/kg, p.o.), and different extracts of the broccoli sprout (200 mg/kg, p.o.). Mice for the donepezil and extract-administered groups were challenged with scopolamine (1.2 mg/kg, i.p.) 30 min after drug administration. Donepezil is a well-known acetylcholine esterase inhibitor and is widely used as a positive control for the scopolamine-induced memory impairment model [28, 29]. Scopolamine-administered and sample treated mice were kept in the center of the maze, and the mice were allowed to enter into the arms of the maze. Mice were let to habituate for 2 min, and their entry in the arms for 8 min was evaluated. Mouse entry is set when the mouse body (from nose to tail) was fully entered into the arms. Only the entry of the mouse in all the 3 different arms consecutively was assigned with point 1 for each arm entered. Alternation behavior was defined as 3 consecutive entries into 3 different arms of the maze. Spatial perception ability was calculated according to the formula below [30].

where N_alterations is the number of times alternation behavior was observed (scored by points), and N_entries is the total number of arm entries.