Autonomic adaptations mediate the effect of hydration on brain functioning and mood: Evidence from two randomized controlled trials

摘要: Dehydration (water loss >2.0% of body weight) has significant negative effects on physical and mental performance. In two studies the minor hypo-hydration <1.0% CNS function, mood cardiovascular functioning were measured. Study 1: On mornings twelve male participants exposed to a temperature 30 °C for four hours either did or not drink 150 ml glasses water during that time. 2: Fifty-six (25 M) individuals same environment randomly allocated (2 × 150 ml) drink. When given 0.59% (Study 1) 0.55% 2) bodyweight was lost. Participant’s heart rate variability (HRV) measured, they rated their thirst mood. study 1, participated in an fMRI protocol which completed modified version Paced Auditory Serial Addition Test (PASAT), at end its difficulty. Decreases BOLD activity orbito-frontal cortex, ventral cingulate gyrus, dorsal hypothalamus, amygdala, right striatum, post-central gyrus superior parietal cortex observed when hypo-hydrated. These deactivations associated with reduced HRV, greater perceived effort, more anxiety. 2 declines HRV found mediate effect ratings data are discussed relation model describes how autonomic regulatory interoceptive processes may contribute affective consequences hypo-hydration.