2.1 Animals
Adult male C57BL/6J mice (9 weeks old) and male CD1 mice (50 weeks old)
were obtained from the Experimental Animal Center of Medical College,
Nanchang University. Before being used, mice were housed five per cage
under standard conditions (12 hours light/dark cycle; lights on from
7:00 to 19:00; 23±1°C ambient temperature; 55±10% relative humidity;
bedding replacement twice a week) for 1 week with free access to food
and water.
Each
experimental group consisted of 20 mice and behavioral experiments were
performed during the light phase. A total of 900 mice were used in these
experiments. For animal sacrifice, all mice were first anaesthetized
using 0.5% pentobarbital sodium (10mL kg-1) and then
killed by cervical dislocation. All animal care and experimental
protocols were conducted in compliance with the Guide for the Care and
Use of Laboratory Animals (8th edition, Institute of Laboratory Animal
Resources on Life Sciences, National Research Council, National Academy
of Sciences, Washington DC) and the guidelines of the Animal Care and
Use Committees of Nanchang University, China. The animals were left
undisturbed for at least one week between testing when used in multiple
models. The home cages were brought into the test room at least 30 min
before each experiment.