Cd1 retired male breeders

CSDS was performed as previously described (Golden et al., 2011 (link); Krishnan et al., 2007 (link)). CD1 retired male breeders (Charles River Laboratory, CA) were single-housed for 3–5 days before CSDS procedures to establish their territorial cage, then pre-screened for aggressive behavior. Experimental C57BL/6J male mice were introduced to the aggressor’s territorial cage, physically contacted and attacked by the aggressor for 5–10 min, and then separated by a clear plastic board with multiple small holes for 24 hr. Experimental mice were introduced to a new CD1 aggressor each day. The no stress control mice were housed with another non-stressed C57BL/6J male mouse, separated by the same plastic board, and the cage partner was changed every day for 10 days of the CSDS experiment.

All experiments performed were approved by the NYUAD Animal Care and Use Committee, and all experimental protocols were conducted according to the National Institute of Health Guide for Care and Use of Laboratory Animals (IACUC Protocol: 150005A2). CD1 retired male breeders (Charles River) and C57BL/6J male mice (8 to 12 weeks; Jackson Laboratories) were used in all experiments of this study. All mice were maintained in the home cages, with ad libitum access (unless noted otherwise) to food and water in temperature (23 ± 2°C)- and humidity (50 ± 10%)-controlled facilities with 12 h light–dark (L/D) cycles (lights on: 7:00 AM; lights off: 7:00 PM, Zeitgeber time ZT; ZT0—lights on; ZT12—lights off). In phase-shift experiments, mice were first entrained to the standard LD cycle after which they were exposed to a 6-h phase advance where lights came on at 1:00 AM and lights off at 1:00 PM. All behavioural tests were conducted during the light cycle (ZT 5 to 10), and mice were habituated to the recording room and lighting conditions for at least 1 h. Between trials, the behavioural apparatus was cleaned with MB-10 solution (Quip Laboratories, United States of America) to avoid persistence of olfactory cues.