All of the mutant strains showed normal fertility and there was no evidence of any health problems. To minimize the potential variability from rearing conditions, all breeding colonies were contained in the same room of vivarium. Mice were group-housed four or five to a cage based on gender and litter. Food and water were available ad libitum. The vivarium was maintained on a 12:12 hr light:dark cycle with lights on at 7.00. The temperature and humidity of the room were kept constant. Behavioral testing began when the mice were at least two months old. All experiments were conducted in isolated behavioral testing rooms in the animal facility to avoid external distractions. All experiments were approved by the Institutional Animal Care and Use Committee.
