The hippocampal response to psychosocial stress varies with salivary uric acid level

Abstract

Uric acid is a naturally occurring, endogenous compound that impacts mental health. In particular, uric acid levels are associated with emotion-related psychopathology (e.g., anxiety and depression). Therefore, understanding uric acid’s impact on the brain would provide valuable new knowledge regarding neural mechanisms that mediate the relationship between uric acid and mental health. Brain regions including the prefrontal cortex, amygdala, and hippocampus underlie stress reactivity and emotion regulation. Thus, uric acid may impact emotion by modifying the function of these brain regions. The present study used functional magnetic resonance imaging (fMRI) during a psychosocial stress task to investigate the relationship between baseline uric acid levels (in saliva) and brain function. Results demonstrate that activity within the bilateral hippocampal complex varied with uric acid concentrations. Specifically, activity within the hippocampus and surrounding cortex increased as a function of uric acid level. The current findings suggest that uric acid levels modulate stress-related hippocampal activity. Given that the hippocampus has been implicated in emotion regulation during psychosocial stress, the present findings offer a potential mechanism by which uric acid impacts mental health.

Neural response to stress and perceived stress differ in patients with left temporal lobe epilepsy

“…Psychosocial stress decreases hippocampal activity and ultimately leads to disinhibition that results in the subsequent increase in arousal that is characteristic of the stress response (Dedovic et al, 2005;Goodman et al, 2016;Khalili-Mahani et al, 2010;Pruessner et al, 2008). Signal extractions (bottom panel) separated by group reflect differences in the linear relationship between the neural response to stress and perceived stress between HC, LTLE, LTLE who report stress as a precipitate (LTLES+), and LTLE who report stress is not a precipitate (LTLES−) groups.…”

“…These findings are consistent with hippocampal lesion and stimulation effects on HPA activation (Ulrich-Lai & Herman, 2009). Alternatively, others assessed inhibitory neural mechanisms related to performance demands by comparing arithmetic performance during CMT and SMT conditions (Goodman et al, 2016;Pruessner et al, 2008;Wheelock et al, 2016). Alternatively, others assessed inhibitory neural mechanisms related to performance demands by comparing arithmetic performance during CMT and SMT conditions (Goodman et al, 2016;Pruessner et al, 2008;Wheelock et al, 2016).…”

“…tions (3dClustSim with -acf option) determined the corrected significance threshold with an uncorrected significance threshold of p < .001. A second Monte Carlo simulation was carried out for the hippocampal complex (hippocampus and parahippocampal gyrus) using a small volume correction based on a priori hypotheses for activation in these regions(Goodman et al, 2016;Khalili-Mahani et al, 2010;Pruessner et al, 2008). The results of this simulation yielded a critical cluster-extent volume threshold of 384 mm 3 .…”

“…One approach to investigating the neurobiological basis of stressrelated processing is functional magnetic resonance imaging (fMRI) during the Montreal Imaging Stress Task (MIST; (Dedovic et al, 2005)). MIST is designed to acutely induce mild-to-moderate psychosocial stress and to assess the neural response to stress by comparing the differential fMRI response to stressful (SMT) and control (CMT) math tasks Goodman et al, 2016;Pruessner et al, 2008;Wheelock et al, 2016). Changes in fMRI signal can be compared to hypothalamic-pituitary-adrenal (HPA) axis reactivity (i.e., cortisol secretion), autonomic arousal (i.e., heart rate [HR]), or other measures of emotional disposition (i.e., perceived stress) to assess the neural mechanisms underlying both, emotional behavior and dispositions Pruessner et al, 2008;Wheelock et al, 2016).…”

“…Furthermore, Allendorfer et al, 2014 assessed the neural response to extrinsic negative evaluations by comparing positive and negative auditory feedback during the CMT and SMT conditions. Alternatively, others assessed inhibitory neural mechanisms related to performance demands by comparing arithmetic performance during CMT and SMT conditions (Goodman et al, 2016;Pruessner et al, 2008;Wheelock et al, 2016).…”