Thirst-Dependent Activity of the Insular Cortex Reflects its Emotion-Related Subdivision: A Cerebral Blood Flow Study

• Published in: Neuroscience 2018-07, Vol.383, p.170-177
• Main Authors: Meier, Lea, Federspiel, Andrea, Jann, Kay, Wiest, Roland, Strik, Werner, Dierks, Thomas
• Format: Article
• Language: English
• Subjects: Adult; arterial spin labeling (ASL); Cerebral Cortex - blood supply; Cerebral Cortex - physiology; Cerebrovascular Circulation - physiology; dehydration; Emotions; homeostasis; Humans; Image Processing, Computer-Assisted; insula; Magnetic Resonance Imaging; Male; Thirst - physiology; Young Adult
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2018.04.022

•Examination of cerebral blood perfusion during the parametric progression of thirst.•Subjective thirst, serum parameters and cerebral blood flow across four thirst stages.•Perfusion differences across all thirst stages were found in the posterior insula.•Subjective thirst ratings were associated with perfusion differences in the anterior insula. Recent studies investigating neural correlates of human thirst have identified various subcortical and telencephalic brain areas. The experience of thirst represents a homeostatic emotion and a state that slowly evolves over time. Therefore, the present study aims at systematically examining cerebral perfusion during the parametric progression of thirst. We measured subjective thirst ratings, serum parameters and cerebral blood flow in 20 healthy subjects across four different thirst stages: intense thirst, moderate thirst, subjective satiation and physiological satiation. Imaging data revealed dehydration-related perfusion differences in previously identified brain areas, such as the anterior cingulate cortex, the middle temporal gyrus and the insular cortex. However, significant differences across all four thirst stages (including the moderate thirst level), were exclusively found in the posterior insular cortex. The subjective thirst ratings over the different thirst stages, however, were associated with perfusion differences in the right anterior insula. These findings add to our understanding of the insular cortex as a key player in human thirst – both on the level of physiological dehydration and the level of the subjective thirst experience.