Come gli effetti collaterali di traumi e paure possono essere ereditati attraverso le modificazioni epigenetiche

Exposure to stressful and traumatic events may have deleterious effects on mental and physical health, as it represents a strong risk factor for behavioral disfunction and mental disorders, such as post-traumatic stress disorder (PTSD). Stress-induced psychopathologies have been associated to an aberrant activity of molecules and pathways involved in response to stress, as well as in the correct functioning of brain circuits. Emerging evidence suggests that many of these alterations can be transmitted to subsequent generations, making the offspring more prone to develop psychiatric disorders. Epigenetic modifications seem to be important mediators in the induction of these changes and their persistence across generations. The aim of this thesis is to analyze and discuss some of the more representative and informative studies on this topic. Firstly, will report about experiments performed on C. Elegans and rodents, demonstrating that traumatic exposure can lead to alterations in histone modifications and DNA methylation of genes involved in brain functioning and stress-response pathways, such as BDNF and CRFR. These alterations were found both in exposed-animal models and in their offspring. Furthermore, I will discuss epigenetic surveys performed on people who survived to Holocaust, fought wars or underwent other traumatic historical events. Convergent data showed in those people epigenetic alterations that were transmitted to their children. The possible mechanisms explaining the intergenerational inheritance are discussed, together with its possible evolutionary significance. Understanding of epigenetic inheritance could lead to the identification of trauma markers, with the perspective to adopt psychological and/or pharmacological preventions and treatments, where necessary.