Hormonal contraceptive exposure relates to changes in resting state functional connectivity of anterior cingulate cortex and amygdala

Abstract

IntroductionHormonal contraceptives (HCs), nowadays one of the most used contraceptive methods, downregulate endogenous ovarian hormones, which have multiple plastic effects in the adult brain. HCs usually contain a synthetic estrogen, ethinyl-estradiol, and a synthetic progestin, which can be classified as androgenic or anti-androgenic, depending on their interaction with androgen receptors. Both the anterior cingulate cortex (ACC) and the amygdala express steroid receptors and have shown differential functionality depending on the hormonal status of the participant and the use of HC. In this work, we investigated for the first time the relationship between ACC and amygdala resting state functional connectivity (rs-FC) and HC use duration, while controlling for progestin androgenicity.MethodsA total of 231 healthy young women participated in five different magnetic resonance imaging studies and were included in the final analysis. The relation between HC use duration and (i) gray matter volume, (ii) fractional amplitude of low-frequency fluctuations, and (iii) seed-based connectivity during resting state in the amygdalae and ACC was investigated in this large sample of women.ResultsIn general, rs-FC of the amygdalae with frontal areas, and between the ACC and temporoparietal areas, decreased the longer the HC exposure and independently of the progestin’s androgenicity. The type of HC’s progestin did show a differential effect in the gray matter volume of left ACC and the connectivity between bilateral ACC and the right inferior frontal gyrus.

Testosterone and the Amygdala’s Functional Connectivity in Women and Men

“…These sex differences might further be affected by confounding variables such as gender stereotypes [96,101] or time limits [102]. The functional organization of the brain seems to be dynamic, associated with endogenous and exogenous sex hormones (e.g., [103][104][105]), and related to further confounding variables such as stress, social behavior, environment, or genotype [106,107]. Testosterone seems to affect variables such as risk-taking behavior, aggression, and sexuality (e.g., [10,108]), which might further be associated with confounding variables such as socio-economic background.…”