In this randomized double blind study, 52 healthy participants were injected with either 0.6 ng/kg body weight or placebo to test if changes in pain sensitivity is associated with change in neural activity using BOLD MR scanning.
Name: EndotoxinDescription: Endotoxin at 0.6 ng/kg of body weight administered intravenously (Escherichia Coli, Lot nr G3E0609, United States Pharmacopeia Rockville, MD)Type: Biological
Name: PlaceboDescription: Saline administered intravenouslyType: Biological
Description: Both deep and cutaneous pain at threshold and suprathreshold noxious levels. Heat- and cold (cutaneous) pain sensitivity was assessed for threshold stimuli and intense noxious stimuli, as well as pressure (deep) pain thresholds and CPM (descending pain inhibition).Measure: Pain sensitivity (cutaneous and deep) Time: 7.5 hours
Description: BOLD activity from MR scans Functional connectivity of the insular cortex during acute inflammation, in relation to symptoms of sickness. Changes in central pain mechanism during acute inflammation, assessed as activity in the insula and areas of the descending pain inhibitory pathways in the brain. Changes in brain function during an emotional task with an interoceptive component during acute inflammation.Measure: Brain function Time: 7.5 hours
Description: "How is your health right now?" rated on a 7 point Likert scale at baseline, after 90 minutes and after 4.5 hours. "How do you rate your general state of health?" rated on a 5-point Likert scale at 90 minutes post-injectionMeasure: Self-rated health Time: 4.5 hours
Description: Photos were taken under standardised conditions before and after injectionMeasure: Facial appearence Time: 2 h
There is one SNP
The study and the procedures used in the study are described in detail here: https://openarchive.ki.se/xmlui/bitstream/handle/10616/44650/Thesis_Bianka_Karshikoff.pdf?seq uence=8&isAllowed=y The following papers using data from this study is published: Lindstedt F, Karshikoff B, Schalling M, Olgart Hoglund C, Ingvar M, Lekander M & Kosek E. Serotonin-1A Receptor Polymorphism (rs6295) Associated with Thermal Pain Perception.