The mice will be anesthetized using isoflurane inhalation for 2-5 minutes in a covered glass bell jar or vaporizer-controlled tank. The waste isoflurane will be trapped with a commercial filter and the amount trapped will be monitored by the increase in weight. Mouse breathing will be checked once every minute by visual inspection. The anesthetic dose will be lowered for animals that are observed to be struggling for a normal breathing pattern. The anesthetic dose will be raised for animals that retract their feet after a firm toe pinch.