Mild inflammation causes a reduction in resting-state amplitude of low-frequency fluctuation in healthy adult males. (August 2020)

• Record Type: Journal Article
• Authors: Stefanov, Kristian; McLean, John; Allan, Becky; Cavanagh, Jonathan; Krishnadas, Rajeev
• Is Part Of: Brain and neuroscience advances. Volume 4(2020)
• Publication Date: 2020-08
• Subjects: Inflammation -- mood disorders -- functional neuroimaging; Brain -- Periodicals; Neurosciences -- Periodicals; Brain; Nervous System; Brain; Neurosciences; Periodicals; Periodical; 616.8
• DOI: 10.1177/2398212820949353
• Languages: English
• ISSNs: 2398-2128

Abstract

Systemic inflammation has been associated with negative mood states and human sickness behaviour. Previous studies have shown an association between systemic inflammation and changes in task-related blood-oxygen-level-dependent activity and functional connectivity within large-scale networks. However, no study has examined the effect of inflammation on the magnitude of blood-oxygen-level-dependent low-frequency fluctuations at rest. We used a double-blind placebo-controlled crossover design to randomise 20 male subjects (aged 20–50 years) to receive either a Salmonella typhi vaccine or a placebo saline injection at two separate sessions. All participants underwent a resting-state functional magnetic resonance scan and a measure of inflammation (interleukin 6) and mood (Profile of Mood States) 3 h after injection. We compared the whole brain amplitude of low-frequency fluctuations between the vaccine and placebo conditions using a repeated measures design. Vaccine condition was associated with greater interleukin 6 levels (p < 0.001). Vaccine condition was also associated with lower amplitude of low-frequency fluctuations in the right and left frontal pole, superior frontal gyrus, paracingulate gyrus (Cluster 1) and the right mid and inferior frontal gyrus (Cluster 2) (p < 0.001, false discovery rate corrected). Lower amplitude of low-frequency fluctuations pertaining to first cluster correlated with greater total Profile of Mood States score (worse mood) (r = −0.38; p = 0.04). These results imply possible excitation/inhibition imbalance mechanisms during inflammation that may be a relevant target in psychiatric disease, especially mood disorders.