Refinement of the stress-enhanced fear learning model of post-traumatic stress disorder: a behavioral and molecular analysis.

Post-traumatic stress disorder (PTSD) is a debilitating mental health condition for which current treatments have long-term efficacy in 50% of patients. There is a clear need for better understanding of the mechanisms underlying PTSD and the development of new treatment approaches. Analog trauma procedures in animals, such as the stress-enhanced fear learning (SEFL) procedure, can be used to produce behavioral and neurobiological changes that have validity in modeling PTSD. However, by necessity, the modeling of PTSD in animals requires them to potentially experience pain and suffering. Consistent with the '3Rs' (reduction, refinement and replacement) of animal research, this study aimed to determine whether the SEFL procedure can be refined to reduce potential animal pain and suffering while retaining the same behavioral and neurobiological changes. Here we showed that PTSD-relevant changes could be produced in both behavior and the brain of rats that were group- rather than single-housed and that received lower-magnitude electric shocks in the 'trauma analog' session. We also varied the number of shock exposures in the trauma analog session, finding SEFL-susceptible and SEFL-resilient populations at all levels of shock exposure, but with greater levels of shock increasing the proportion of rats showing the SEFL-susceptible phenotype. These data demonstrate that the SEFL procedure can be used as an animal analog of PTSD with reduced potential pain and suffering to the animals and that variations in the procedure could be used to generate specific proportions of SEFL-susceptible and SEFL-resilient animals in future studies.

Trazodone and patient outcomes in dementia-Limitations of naturalistic cohort data.

The unfolded protein response has been increasingly implicated as an important pathological pathway and target for therapeutic intervention in neurodegeneration. The licensed antidepressant trazodone is one drug which has been proposed to act on this pathway and may therefore be a potential therapy. Previous examination of existing data for patients with dementia prescribed trazodone did not find a signal suggesting a disease modifying effect. Here we add to that literature by examining the electronic patient record of patients with dementia in Cambridgeshire UK. We found that trazodone is rarely prescribed and where it is used it is at a dose less than half that predicted to be disease modifying. We also found that patients prescribed trazodone had higher levels of neuropsychiatric symptoms and were relatively late in the disease course, likely beyond the optimal point for therapeutic intervention. We suggest it is therefore premature to discard potential therapies based on observational data alone, particularly when experimental medicine approaches to examine the effects of trazodone are feasible.