Chronic stress during adolescence evokes a resilient phenotype after single prolonged stress: Implications for PTSD study?

COTELLA, EVELIN M.; LEMEN, PAIGE; BEDEL, NICHOLAS; HERMAN, JAMES P.

Washington D.C.

Congreso; Annual Meeting Society for Neuroscience; 2017

Chronic stress during adolescence evokes a resilient phenotype after single prolonged stress: Implications for PTSD studyCotella, E.M.; Lemen P.; Bedel N.; Herman J.P.Posttraumatic stress disorder (PTSD) is a psychiatric condition that can develop after the individual is exposed to traumatic experience. Not everybody that experiences trauma develops the disorder since even though the probability of facing a trauma during life is 75% in the USA, the prevalence of PTSD is about 6.8 %. This suggests there must be a mechanism that confers more resilience to some individuals to overcome the traumatic experience while other ones are at higher risk of developing the condition. Our hypothesis is that chronic variable stress (CVS) during adolescence will predispose rats to development of PTSD-related behaviors in adulthood. Rats of both sexes were subjected to either chronic variable stress (CVS) for a 2-weeks starting at PND44. Stressors were presented randomly twice daily (cage vibration, cold water swim, warm water swim, cold room, hypoxia, or restraint) and every 2-3 days they had overnight stressors (single housing or overcrowding).At 85 days of age, a group of the rats was subjected to a single-prolonged stress (SPS). They were restrained for 2 hours, followed by 20 minutes of group swim. Immediately after they were allowed to recover for 10 minutes before being exposed to ether vapor until loss of consciousness. The resulting groups were: Control, Adol CVS, SPS and the double-hit group Adol CVS+SPS. After a week, animals? performance in an auditory-cued fear conditioning paradigm was tested. There were no differences in acquisition of freezing in response to the pairing of the shock to the auditory tone in any group or sex. During extinction, SPS males increased freezing behavior during all extinction sessions (p