2.1 Animals
Adult male Sprague‒Dawley rats (RRID: MGI: 5651135) (250-280 g weight)
were procured from the Animal Center of Peking University (Beijing,
China). The rats were housed individually in plastic cages with ad
libitum access to food and water at an optimum temperature of 25 ± 2°C
and 55-65% relative humidity. The position of the bottle was in the
middle of the cage cover to eliminate location bias. A 12 h/12 h
light/dark cycle (lights on at 9:00 AM) was regulated in the animal
house. All rats were allowed to acclimate for 7 d before receiving any
experimental manipulation. All the experimental procedures were carried
out under the guidelines of the ”Animal Research: Reporting of In Vivo
Experiments (ARRIVE)”(Percie du Sert, Hurst et al., 2020) and the
recommendations made by the British Journal of Pharmacology
(BJP)(Lilley, Stanford et al., 2020). The animal experiment protocol was
approved by the Peking University Committee on Animal Care and Use
(permission no. LA 2020279).