BACKGROUND: Findings about sex differences in the field of fear conditioning and fear extinction have been mixed. At the psychophysiological level, sex differences emerge only when taking @entity53 levels of @entity1 into consideration. This suggests that this hormone may also influence sex differences with regards to activations of brain regions involved in fear conditioning and its extinction. Importantly, the neurobiological correlates associated with the use of hormonal @entity7280 in @entity1 have not been fully contrasted against @entity1 and against naturally cycling @entity1 with different levels of @entity53 . In this study, we begin to fill these scientific gaps. METHODS: We recruited 37 healthy @entity1 and 48 healthy @entity1 . Of these @entity1 , 16 were using @entity7280 (OC) and 32 were naturally cycling. For these naturally cycling @entity1 , a median split was performed on their serum @entity53 levels to create a high @entity53 (HE) group (n   =   16) and a low @entity53 (LE) group (n   =   16). All @entity1 underwent a 2-day fear conditioning and extinction paradigm in a 3  T MR scanner. Using the 4 groups ( @entity1 , HE @entity1 , LE @entity1 , and OC users) and controlling for age and coil type, one-way ANCOVAs were performed to look at significant activations within the nodes of the fear circuit. Using post-hoc analyses, beta-weights were extracted in brain regions showing significant effects in order to unveil the differences based on hormonal status ( @entity1 , HE, LE, OC). RESULTS: Significant main effect of hormonal status group was found across the different phases of the experiment and in different sub-regions of the insular and cingulate cortices, amygdala, hippocampus, and @entity2339 . During conditioning, extinction and recall, most of the observed differences suggested higher activations among HE @entity1 relative to @entity1 . During the unconditioned response, however, a different pattern was observed with @entity1 showing significantly higher brain activations. CONCLUSIONS: Our data further support the important contribution of @entity53 levels in the activation of brain regions underlying fear learning and extinction. The results highlight the need to document gonadal hormonal levels, menstrual cycle phase as well as oral contraceptive use in @entity1 in order to avoid overlooking sex differences when investigating the neurobiology of emotional regulation.

Contribution of XXXX levels and hormonal contraceptives to sex differences within the fear network during fear conditioning and extinction.

@entity1 :: ('9606', 'Species') :: ['participants', 'women', 'men'] @entity7280 :: ('MESH:D003276', 'Chemical') :: ['oral contraceptives'] @entity2339 :: ('MESH:D007029', 'Disease') :: ['hypothalamus'] @entity53 :: ('MESH:D004958', 'Chemical') :: ['estradiol']
@entity53 :: (MESH:D004958,Chemical) :: ['estradiol']
