Sleep deprivation procedure The setup used in this study was a modified multi-platform container made of plastic that have been explained earlier (Kamali et al., 2016[12]). The container was then filled with water. When a rat entered the sleep, it touched the water by tilting its head downwards or fell into the water due to muscle atonia. The SD period continued for 21 days during which the rats were kept in the multiple-platform box for 18 hours from 6:00 P.M. to 12:00 noon on the subsequent day. During the next 6 hours, the rats were permitted to fall asleep (12:00 noon to 6:00 pm). The light schedule of the SD-boxes, on from 6:00 A.M. until 6:00 P.M, was in accordance with the light/dark cycle similar to the non-SD animals (Wang et al., 2014[27]). In the grid groups (VII, VIII, IX), the rats were located on wire-mesh grids in the deprivation container. The grid was made of stainless steel. This was incorporated as a control group for SD. Finally, the rats in these groups also underwent the eight-arm radial maze test.