Seventy day old male Sprague-Dawley rats (300 g; University of British Columbia Breeding Center) were used in this study. The rats were pair housed (except following surgical procedures, when they were individually housed) in standard maternity bins lined with contact bedding. Colony rooms were maintained at 21 °C, and on a 12 h light/dark cycle, with lights on at 0900h. All rats were given ad libitum access to Purina Rat Chow and tap water. All protocols were approved by the Canadian Council for Animal Care and the Animal Care Committee of the University of British Columbia. All studies occurred during the first third of the light cycle, during the daily nadir of HPA axis activity.
