Torrisi SA, Lavanco G, Maurel OM, Gulisano W, Laudani S, Geraci F, Grasso M, Barbagallo C, Caraci F, Bucolo C, Ragusa M, Papaleo F, Campolongo P, Puzzo D, Drago F, Salomone S, Leggio GM. A novel arousal-based individual screening reveals susceptibility and resilience to PTSD-like phenotypes in mice.
Neurobiol Stress 2020;
14:100286. [PMID:
33392367 PMCID:
PMC7772817 DOI:
10.1016/j.ynstr.2020.100286]
[Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/21/2020] [Accepted: 12/06/2020] [Indexed: 12/11/2022] Open
Abstract
Translational animal models for studying post-traumatic stress disorder (PTSD) are valuable for elucidating the poorly understood neurobiology of this neuropsychiatric disorder. These models should encompass crucial features, including persistence of PTSD-like phenotypes triggered after exposure to a single traumatic event, trauma susceptibility/resilience and predictive validity. Here we propose a novel arousal-based individual screening (AIS) model that recapitulates all these features. The AIS model was designed by coupling the traumatization (24 h restraint) of C57BL/6 J mice with a novel individual screening. This screening consists of z-normalization of post-trauma changes in startle reactivity, which is a measure of arousal depending on neural circuits conserved across mammals. Through the AIS model, we identified susceptible mice showing long-lasting hyperarousal (up to 56 days post-trauma), and resilient mice showing normal arousal. Susceptible mice further showed persistent PTSD-like phenotypes including exaggerated fear reactivity and avoidance of trauma-related cue (up to 75 days post-trauma), increased avoidance-like behavior and social/cognitive impairment. Conversely, resilient mice adopted active coping strategies, behaving like control mice. We further uncovered novel transcriptional signatures driven by PTSD-related genes as well as dysfunction of hypothalamic–pituitary–adrenal axis, which corroborated the segregation in susceptible/resilient subpopulations obtained through the AIS model and correlated with trauma susceptibility/resilience. Impaired hippocampal synaptic plasticity was also observed in susceptible mice. Finally, chronic treatment with paroxetine ameliorated the PTSD-like phenotypes of susceptible mice. These findings indicate that the AIS model might be a new translational animal model for the study of crucial features of PTSD. It might shed light on the unclear PTSD neurobiology and identify new pharmacological targets for this difficult-to-treat disorder.
The AIS model includes highly requested features necessary to shape a translational PTSD animal model.
Susceptible mice identified through the AIS model exhibited persistent PTSD-like phenotypes.
Resilient mice identified through the AIS model adopted active coping strategies.
The AIS model revealed molecular adaptations underlying trauma susceptibility/resilience.
The AIS model meets the criterion of predictive validity by exclusively using susceptible mice.
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