Aidan Evans-Strong, Najah Walton, Katrina Blandino, Abigail T. C. Roper, S. Tiffany Donaldson, Mike Lewis, Jamie Maguire
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引用次数: 0
Abstract
Neurosteroids have been implicated in the pathophysiology of post-traumatic stress disorder (PTSD). Allopregnanolone is reduced in subsets of individuals with PTSD and has been explored as a novel treatment strategy. Both direct trauma exposure and witnessed trauma are risk factors for PTSD; however, the role of neurosteroids in the behavioral outcomes of these unique experiences has not been explored. Here, we investigate whether observational fear is associated with a reduced capacity for endogenous neurosteroidogenesis and the relationship with behavioral outcomes. We demonstrated that mice directly subjected to a threat (foot shocks) and those witnessing the threat have decreased plasma levels of allopregnanolone. The expression of a key enzyme involved in endogenous neurosteroid synthesis, 5α-reductase type 2, is decreased in the basolateral amygdala, which is a major emotional processing hub implicated in PTSD. We demonstrated that genetic knockdown or pharmacological inhibition of 5α-reductase type 2 exaggerates the behavioral expression of fear in response to witnessed trauma, whereas oral treatment with an exogenous, synthetic neuroactive steroid gamma-aminobutyric acid-A receptor positive allosteric modulator with molecular pharmacology similar to allopregnanolone (SGE-516 [tool compound]) decreased the behavioral response to observational fear. These data implicate impaired endogenous neurosteroidogenesis in the pathophysiology of threat exposure, both direct and witnessed. Further, these data suggest that treatment with exogenous 5α-reduced neurosteroids or targeting endogenous neurosteroidogenesis may be beneficial for the treatment of individuals with PTSD, whether resulting from direct or witnessed trauma.
期刊介绍:
Journal of Neuroendocrinology provides the principal international focus for the newest ideas in classical neuroendocrinology and its expanding interface with the regulation of behavioural, cognitive, developmental, degenerative and metabolic processes. Through the rapid publication of original manuscripts and provocative review articles, it provides essential reading for basic scientists and clinicians researching in this rapidly expanding field.
In determining content, the primary considerations are excellence, relevance and novelty. While Journal of Neuroendocrinology reflects the broad scientific and clinical interests of the BSN membership, the editorial team, led by Professor Julian Mercer, ensures that the journal’s ethos, authorship, content and purpose are those expected of a leading international publication.