title: The effects of a reminder of underwater trauma on behaviour and memory-related mechanisms in the rat dentate gyrus.
abstract: Intrusive re-experiencing is a core symptom in post-traumatic stress disorder (PTSD), often triggered by contextual cues associated with the trauma. It is not yet clear if intrusive re-experiencing is only the result, or whether it may contribute to the establishment of PTSD following acute stress. This study aimed at examining the impact of an underwater trauma (UWT) reminder on anxiety-like behaviour and on neuronal activity and plasticity in the hippocampus and the amygdala. Sprague-Dawley rats were exposed to UWT and 24 h later were re-exposed to the context. The effects on behaviour, activation of the amygdala (BLA) and dentate gyrus (DG), and on long-term potentiation (LTP) and local circuit activity (frequency-dependent inhibition (FDI) and paired-pulse inhibition (PPI)) in the DG were assessed. The exposure to UWT by itself resulted in increased anxiety behaviour in the open field, together with increased PPI. Upon exposure to the UWT reminder, an additional increase in anxiety was also observed in the EPM and in FDI. Moreover, reminder exposure resulted in impaired DG LTP and a significant BLA extracellular-signal-regulated kinases (ERK) 2 activation. In conclusion, these observed effects of exposure to a trauma reminder, following the exposure to the initial trauma, might be associated with the progression of trauma-related pathologies and the development of related disorders.
authors.affiliation: Department of Psychology, University of Haifa, Haifa 31905, Israel.
authors.forename: Ziv
authors.initials: Z
authors.lastname: Ardi
authors.affiliation: Department of Psychology, University of Haifa, Haifa 31905, Israel.
authors.forename: Gilad
authors.initials: G
authors.lastname: Ritov
authors.affiliation: The Institute for the Study of Affective Neuroscience, University of Haifa, 31905 Haifa, Israel.
authors.forename: Morgan
authors.initials: M
authors.lastname: Lucas
authors.affiliation: Department of Psychology, University of Haifa, Haifa 31905, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Richter-Levin
mesh_terms: D000679:Amygdala / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D018891:Dentate Gyrus / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D018408:Patch-Clamp Techniques; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013313:Stress Disorders, Post-Traumatic / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*