title: Effects of individual glucose levels on the neuronal correlates of emotions.
abstract: This study aimed to directly assess the effect of changes in blood glucose levels on the psychological processing of emotionally charged material. We used functional magnetic resonance imaging (fMRI) to evaluate the effect of blood glucose levels on three categories of visually presented emotional stimuli. Seventeen healthy young subjects participated in this study (eight females; nine males; body weight, 69.3 ± 14.9 kg; BMI, 22 ± 2.7; age, 24 ± 3 years), consisting of two functional MRI sessions: (1) after an overnight fast under resting conditions (before glucose administration); (2) after reaching the hyperglycemic state (after glucose administration). During each session, subjects were presented with visual stimuli featuring funny, neutral, and sad content. Single-subject ratings of the stimuli were used to verify the selection of stimuli for each category and were covariates for the fMRI analysis. Analysis of the interaction effect of the two sessions (eu- and hyperglycemia), and the emotional categories accounting for the single-subject glucose differences, revealed a single activation cluster in the hypothalamus. Analysis of the activation profile of the left amygdala corresponded to the three emotional conditions, and this profile was obtained for both sessions regardless of glucose level. Our results indicate that, in a hyperglycemic state, the hypothalamus can no longer respond to emotions. This study offers novel insight for the understanding of disease-related behavior associated with dysregulation of glucose and glucose availability, potentially offering improved diagnostic and novel therapeutic strategies in the future.
authors.affiliation: MR Centre of Excellence, Medical University Vienna Vienna, Austria ; Center of Medical Physics and Biomedical Engineering, Medical University Vienna Vienna, Austria ; Division of Neuro- and Musculoskeletal Radiology, Department of Radiology, Medical University Vienna Vienna, Austria.
authors.forename: Veronika
authors.initials: V
authors.lastname: Schöpf
authors.forename: Florian Ph S
authors.initials: FP
authors.lastname: Fischmeister
authors.forename: Christian
authors.initials: C
authors.lastname: Windischberger
authors.forename: Florian
authors.initials: F
authors.lastname: Gerstl
authors.forename: Michael
authors.initials: M
authors.lastname: Wolzt
authors.forename: Karl Æ
authors.initials: KÆ
authors.lastname: Karlsson
authors.forename: Ewald
authors.initials: E
authors.lastname: Moser
keywords: emotion processing; functional MRI; hyperglycemia; hypoglycemia; hypothalamus