Maternal factors in a mouse model of posttraumatic stress disorder

In large twin studies, 20–30 percent genetic contribution to the development of Posttraumatic Stress Disorder (PTSD) have been postulated (True, Rice et al., 1993;Xian, Chantarujikapong et al., 2000). However, genetics, epigenetics and early upbringing conditions are closely intertwined and hardly to distinguish in human studies. We approached this issue by comparing the influence of maternal experience (1st, 2nd, 3rd litter) and early upbringing conditions (enriched, non-enriched) on the development of fear after an aversive encounter in two inbred mouse strains (C57BL/6JOla, C57BL/6N) that have recently been shown to differ in the development of PTSD related symptoms in our group. Genetics, epigenetics and early environmental conditions proved to have an interactive impact on both associative and non-associative fear components after a traumatic incident.