Experimental animals
Adult male Wistar rats, weighing 250–300 g and 8 weeks old, were sourced from the Animal Experiment Center of Nanjing Medical University’s Affiliated Nanjing Hospital. They were housed under the constant temperature and humidity (24 ± 2 ℃, and 50 ± 5%). All animals were housed in a group of three per cage (cage type: 46cm×35cm×20cm ventilated cage). All rats were euthanized by intraperitoneal injection of 10% chloral hydrate after the behavioural experiments. All animal experiments were approved by the experimental Animal Welfare and Ethics Committee.