title: Effects of multiple brief exposures to trauma-associated cues on traumatized resilient and vulnerable rats.
abstract: Intrusive re-experiencing of a trauma is a core symptom in post-traumatic stress disorder (PTSD), and is often triggered by contextual cues associated with the event. It is not yet established if intrusive re-experiencing is the consequence of PTSD, or if it could contribute to the development of PTSD following a traumatic event. The present study (1) examined the impact of repeated brief re-exposures to trauma reminders on the strength of PTSD-like symptoms, as well as on their time-development and (2) investigated the reactivity over time to these cues in trauma resilient and vulnerable rats, defined on the basis of the PTSD-like symptoms they demonstrated. Rats were exposed to a Single Prolonged Stress, combining three different stresses (2-h restraint, 20-min forced swim and CO2unconsciousness) delivered together with tone and odor cues and preceded by an inhibitory avoidance conditioning or a control procedure. During the following two weeks, reminded rats were briefly re-exposed to trauma-associated cues either 4 or 8 times. The results indicated that 4 re-exposures to the same cue strengthened PTSD-like symptoms (anxiety, arousal, fear to trauma-cue). However 8 re-exposures to similar or different trauma-cues did not alter PTSD-like symptoms and led to a rapid extinction of the fear reactivity to these cues. The present results further indicated that shortly after trauma, both resilient and vulnerable rats strongly reacted to trauma-associated cues, while only vulnerable rats reacted long after the trauma, suggesting a slower loss of fear responses to trauma cues in these rats. We concluded that re-experiencing may participate in, but cannot be solely responsible for, the development of long-term PTSD effects.
authors.affiliation: Neuro-PSI, Université Paris-Sud, CNRS UMR9197, Université Paris-Saclay, Orsay, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Le Dorze
authors.affiliation: Neuro-PSI, Université Paris-Sud, CNRS UMR9197, Université Paris-Saclay, Orsay, France. Electronic address: pascale.gisquet@u-psud.fr.
authors.forename: Pascale
authors.initials: P
authors.lastname: Gisquet-Verrier
mesh_terms: D000818:Animals; D001007:Anxiety; D001143:Arousal; D001362:Avoidance Learning; D002248:Carbon Monoxide; D003213:Conditioning, Psychological; D003463:Cues; D004195:Disease Models, Animal; D008297:Male; D009812:Odorants; D011581:Psychological Tests; D017207:Rats, Sprague-Dawley; D055500:Resilience, Psychological; D012149:Restraint, Physical; D013016:Sound; D013313:Stress Disorders, Post-Traumatic; D013315:Stress, Psychological; D013550:Swimming; D013997:Time Factors; D014474:Unconsciousness
chemical_list: D002248:Carbon Monoxide
keywords: PTSD-like symptoms; Rats; Re-experiencing; Single Prolonged Stress (SPS); Trauma-associated cues; Vulnerability