Serotonergic modulation of resting state default mode network connectivity in healthy women

• Published in: Amino acids Vol. 48; no. 4; pp. 1109 - 1120
• Main Authors: Helmbold, K., Zvyagintsev, M., Dahmen, B., Biskup, C. S., Bubenzer-Busch, S., Gaber, T. J., Klasen, M., Eisert, A., Konrad, K., Habel, U., Herpertz-Dahlmann, B., Zepf, F. D.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.04.2016; Springer Nature B.V
• Subjects: Adult; Affect - drug effects; Affect - physiology; Amino acids; Amino Acids - administration & dosage; Analytical Chemistry; Biochemical Engineering; Biochemistry; Biomedical and Life Sciences; Brain Mapping; Cognition - drug effects; Cognition - physiology; Correlation; Cross-Over Studies; Depletion; Double-Blind Method; Female; Follicular Phase - physiology; Frontal Lobe - anatomy & histology; Frontal Lobe - drug effects; Frontal Lobe - physiology; Humans; Impulsive Behavior - drug effects; Impulsive Behavior - physiology; Life Sciences; Magnetic Resonance Imaging; Modulation; Nerve Net - anatomy & histology; Nerve Net - drug effects; Nerve Net - physiology; Networks; Neurobiology; Original Article; Parietal Lobe - anatomy & histology; Parietal Lobe - drug effects; Parietal Lobe - physiology; Proteomics; Rest - physiology; Rest - psychology; Serotonin; Serotonin - biosynthesis; Synthesis; Thinking - drug effects; Thinking - physiology; Tryptophan - administration & dosage; Tryptophan - deficiency; Functional connectivity; Default mode network; Impulsivity; Resting state; Serotonin; Tryptophan depletion
• ISSN: 0939-4451; 1438-2199
• DOI: 10.1007/s00726-015-2137-4

The default mode network (DMN) plays a central role in intrinsic thought processes. Altered DMN connectivity has been linked to diminished cerebral serotonin synthesis. Diminished brain serotonin synthesis is further associated with a lack of impulse control and various psychiatric disorders. Here, we investigated the serotonergic modulation of intrinsic functional connectivity (FC) within the DMN in healthy adult females, controlling for the menstrual cycle phase. Eighteen healthy women in the follicular phase (aged 20–31 years) participated in a double-blind controlled cross-over study of serotonin depletion. Acute tryptophan depletion (ATD) and a balanced amino acid load (BAL), used as the control condition, were applied on two separate days of assessment. Neural resting state data using functional magnetic resonance imaging (fMRI) and individual trait impulsivity scores were obtained. ATD compared with BAL significantly reduced FC with the DMN in the precuneus (associated with self-referential thinking) and enhanced FC with the DMN in the frontal cortex (associated with cognitive reasoning). Connectivity differences with the DMN between BAL and ATD in the precentral gyrus were significantly correlated with the magnitude of serotonin depletion. Right medial frontal gyrus and left superior frontal gyrus connectivity differences with the DMN were inversely correlated with trait impulsivity. These findings partially deviate from previous findings obtained in males and underline the importance of gender-specific studies and controlling for menstrual cycle to further elucidate the mechanism of ATD-induced changes within intrinsic thought processes.