SpecialityUniversità di Pisa, IT

Hormonal modulation of functional brain-heart interplayHormonal modulation of functional brain-heart interplay Laura Sebastiani1,2, Vincenzo Catrambone3,4, Lorenzo Zallocco 1, Maria Rosa Mazzoni 5, Laura Giusti6, Gaetano Valenza 3,4 1 Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa. 2 Institute of Information Science and Technologies "Alessandro Faedo" (ISTI-CNR), Pisa. 3 Bioengineering and Robotics Research Center E. Piaggio, University of Pisa 4 Department of Information Engineering, School of Engineering, University of Pisa 5 Department of Pharmacy, University of Pisa 6 School of Pharmacy, University of Camerino Dynamic information exchange between the central and autonomic nervous systems, termed functional brain-heart interaction (BHI), can be studied using the sympathovagal synthetic data generation model (Catrambone et al., 2019), a computational framework according to which time-varying directional biomarkers of BHI represent an immediate assessment of heart-to-brain and brain-to-heart interactions for combinations of EEG and heart rate variability (HRV) frequency components (LF, HF), respectively. This study aims to investigate the bidirectional BHI involved in test anxiety and its possible modulation by female sex hormones. Twenty-four healthy females recruited either in the pre-ovulatory (n=11, group Pre-ov) or post-ovulatory phase (n=13, group Post-ov) of the menstrual cycle, characterized, respectively, by low and high levels of estradiol and progesterone, participated to a test anxiety task. The task simulated an oral exam and consisted of 3 phases: open eyes resting state (R, 2 min), study of a written text (S, 3 min), and oral exposition in front of a “professor” of the studied text (Interrogation phase, I, 2 min). EEG from 16 active electrodes and ECG from 2 electrodes placed on the chest were recorded using the wireless amplifier g.Nautilus 32 Multi-purpose system (gTech) and the g.Recorder software. For each experimental phase the median values across time were considered, for all BHI-, EEG-, and HRV- derived measures. Group-wise comparison by means of Friedman test for paired test, shows significant differences that involves almost the entire scalp, in the brain-to-LF interplay for all the considered EEG frequency bands (delta, theta, alpha, beta). These differences are associated with the I phase, which has lower BHI measures than R and S phases (Wilcoxon test). Friedman test shows significant differences also in LF-to-brain (in the posterior-central region considering delta, theta, alpha, and in the frontal area for delta and in HF-to-brain interplay (in the bilateral frontal area, in the right frontal area, and in the posterior-central area for delta, theta and alpha bands, respectively). These differences are related to the S phase, which appears to have lower BHI measures than both R and I phase. Comparison between Pre- and Post-ov groups reveals significant differences in the the S phase, where the Post-ov group shows higher brain-to-HF interplay for all the EEG-related frequency bands than the Pre-ov one, at central scalp regions. Pearson correlation analysis, reveals significant associations in the I phase of the Pre-ov group, between brain-to-HF measures, in all the EEG-frequency bands, and the level of progesterone. Our results suggest that test anxiety induces dynamic fluctuations within brain-body networks including bidirectional interactions at a brain-heart level and that the brain-to-body interplay may be modulated by the menstrual cycle phase.