Biology subjects

Kimmig, A.-C. S.

Publications and source records attributed to Kimmig, A.-C. S..

4 recordsLinked to original sources

bioRxiv2026

Menstrual cycle phase and premenstrual symptoms in relation with the stress response: an fMRI study

Objective: Women with premenstrual syndrome (PMS) experience affective lability, irritability, depressed mood, and anxiety during the late luteal phase of the menstrual cycle. Stress reactivity may contribute to the development of these symptoms, yet neural correlates remain unexplored. We examined neural, behavioral and endocrine stress responses across menstrual cycle phases in women with and without PMS. Methods: 26 women with PMS and 24 women without PMS participated in two fMRI sessions, during the mid-follicular (days 5 to 11) and late-luteal phases (days -7 to -1). Participants completed the Montreal Imaging Stress Task (MIST). Subjective stress ratings and salivary cortisol were collected at six time points before and after stress induction. Stress-related brain activation was assessed using whole-brain and region-of-interest analyses. Results: Subjective stress ratings increased as expected from before to after the MIST, with no group or phase differences. Salivary cortisol was significantly higher during the mid-follicular phase, with no group effect or significant pre-post MIST difference. While the stress task elicited activation patterns in stress-related regions, whole-brain analysis revealed no significant effects of group (PMS vs. no PMS) or menstrual cycle phase (follicular vs. luteal) on the neural stress response. Considering premenstrual symptom severity as a predictor revealed significant group-by-symptom severity interactions in the right inferior frontal gyrus and the right superior temporal gyrus. Conclusion: Using a within-subject repeated-measures design, we found neural responses to psychosocial stress to be stable across menstrual cycle phases. Individual differences in symptom severity may nevertheless be associated with differences in stress-related brain activation.

neuroscience↗

bioRxiv2026

Stronger brain responses to acute stress reflect greater everyday stress variability

Laboratory stress tasks are widely used to assess individual differences in acute stress reactivity, yet it remains unclear how these responses correspond to stress experienced in everyday life. Here, we combined the Montreal imaging stress task (MIST) with ecological momentary assessment (EMA) over three months to assess acute and everyday stress in 67 healthy women. Greater within-person variability in everyday stress, but not average stress levels, were associated with stronger overall stress-related brain responses (b = 0.73, p = .039), with a whole-brain association particularly evident in the bilateral caudate (rROI = .32, pcluster.FWE < .001). Greater everyday stress variability was also associated with stronger stress-related functional connectivity between the ventromedial prefrontal cortex (vmPFC) and parietal and posterior medial regions (pcluster.FWE < .001). We conclude that acute neural stress responses relate more closely to fluctuations in perceived stress than to how stressed an individual feels on average. This suggests that laboratory stress tasks capture acute stress responsivity that is distinct from average stress exposure, highlighting the importance of considering what these tasks measure when interpreting individual differences in acute stress responses.

neuroscience↗

bioRxiv2025

Inter- and intra-individual differences in brain sex map to neuroendocrine profiles

Sex hormone fluctuations modulate structural and functional brain dynamics, yet little is known how sex steroid levels map onto the expression of sex differences in the brain. Here, we trained machine learning models for brain sex classification based on anatomical structures in cross-sectional data of N = 1090 individuals (50% females, age matched). Applied to dense sampled data of one male and two females in different hormonal states (naturally cycling, oral contraceptive user, pregnancy), we linked inter- and intra-individual fluctuations in brain sex to neuroendocrine modulation. We found lower variation in brain sex across time in the male compared to the female subjects. Oral contraceptive use was associated with a more female-like brain, while (inverted) U-shaped brain sex trajectories emerged across menstrual cycle phases and pregnancy trimesters. Overall, our findings suggest that changes in brain sex capture hormone-related plasticity over time in dense sampled individuals.

neuroscience↗

bioRxiv2022

To start or to discontinue the pill - changes in progestogens reflected by resting-state connectivity and positive mood

Oral contraceptive (OC) intake has been associated with alterations in functional brain architecture and socio-affective processes. However, most previous studies have been limited by cross-sectional designs and/or did not account for synthetic sex hormone concentrations. The aim of this longitudinal study was to determine the effects of starting vs discontinuing OCs on socio-affective functions such as mood and emotion cognition, and to identify their possible neuroendocrinological substrates. To this end, 88 young healthy women performed the behavioral and fMRI measures twice, three to eight months apart: 26 natural cycling women twice during menstruation, 26 OC users twice during OC intake, 25 OC discontinuers and 11 OC starters before and after discontinuation or start, respectively. In addition to mean-based analyses, we used intersubject representational similarity analyses to determine relationships between interindividual variability in within-subject changes of hormone profiles, including concentrations of endogenous and synthetic hormones, region-specific resting state functional connectivity (parcelwise RSFC) and socio-affective measures. Across the whole sample, interindividual patterns of changes in RSFC of fronto-parietal regions, parts of the left hippocampus and the right cerebellum reflected change patterns of progestogen levels. For the right superior orbitofrontal gyrus (OFG), a trinity of idiosyncratic patterns was found in changes of progestogens, RSFC and positive mood. Active OC intake was associated with higher self-reported depressive symptoms in OC discontinuers (and starters). Emotion recognition performance was not associated with changes in hormone profiles or RSFC. Overall, progestogens rather than estrogens appear to be associated with functional brain architecture of the frontal and subcortical/cerebellar regions and positive mood. The right superior OFG represents a possible neural substrate for progestogen-induced changes in positive mood. This study indicates the importance of a multidimensional, longitudinal approach when being interested in effects of hormonal contraception on womens brain and behavior.

neuroscience↗