@entity308 ( @entity308 ) is a debilitating disorder of altered mood regulation. Despite well established sex differences in @entity308 prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), @entity308 prevalence is consistently higher in @entity1 across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place @entity1 at higher risk. Studies in @entity1 subjects and in rodent models suggest a developmental origin for @entity1316 , and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to @entity308 may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with @entity251 ) to masculinize sexually dimorphic brain regions in female @entity19 . We then investigated adult behavioral consequences relating to emotionality by comparing neonatal @entity251 -treated females to normal males and females. Under baseline/trait conditions, neonatal @entity251 treatment of female @entity19 did not influence @entity4479 , but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female @entity19 to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal @entity251 exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in @entity4479 in @entity19 are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the @entity1 adult female prevalence of @entity308 .

Neonatal @entity251 partially organizes sex differences in stress-induced emotionality in XXXX .

@entity1 :: ('9606', 'Species') :: ['women', 'human'] @entity251 :: ('MESH:D013739', 'Chemical') :: ['testosterone'] @entity308 :: ('MESH:D003866', 'Disease') :: ['MDD', 'Major depressive disorder'] @entity4479 :: ('MESH:C538052', 'Disease') :: ['adult emotionality'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity1316 :: ('MESH:D019964', 'Disease') :: ['mood disorders']
@entity19 :: (10090,Species) :: ['mice']
