Open AccessGhrelin is a persistent biomarker for chronic stress exposure in adolescent rats and humans
Author(s) -
Muhammad Irfan ul Akbar Yousufzai,
Elia Samuel Harmatz,
Mohsin Shah,
Muhammad Omar Malik,
Ki A. Goosens
Publication year - 2018
Publication title -
translational psychiatry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.652
H-Index - 82
ISSN - 2158-3188
DOI - 10.1038/s41398-018-0135-5
Subject(s) - stressor , ghrelin , biomarker , hormone , medicine , psychology , corticotropin releasing hormone , physiology , endocrinology , clinical psychology , biology , biochemistry
Prolonged stressor exposure in adolescence enhances the risk of developing stress-sensitive mental illnesses, including posttraumatic stress disorder (PTSD), for many years following exposure cessation, but the biological underpinnings of this long-term vulnerability are unknown. We show that severe stressor exposure increased circulating levels of the hormone acyl-ghrelin in adolescent rats for at least 130 days and in adolescent humans for at least 4.5 years. Using a rodent model of longitudinal PTSD vulnerability in which rodents with a history of stressor exposure during adolescence display enhanced fear in response to fear conditioning administered weeks after stressor exposure ends, we show that systemic delivery of a ghrelin receptor antagonist for 4 weeks surrounding stressor exposure (2 weeks during and 2 weeks following) prevented stress-enhanced fear memory. These data suggest that protracted exposure to elevated acyl-ghrelin levels mediates a persistent vulnerability to stress-enhanced fear after stressor exposure ends.