Richard G. Wise1,
Anna Jolly2, Kevin Murphy1, C. John Evans1,
Judith E. Hall2
1CUBRIC, School
of Psychology, Cardiff University, Cardiff, S. Glamorgan, United Kingdom; 2Department
of Anaesthetics & Intensive Care Medicine, School of Medicine, Cardiff
University, Cardiff, S. Glamorgan, United Kingdom
Opioids decrease pain-related signals in line with their analgesic effects but also modify cerebral blood flow in a pattern consistent with their receptor distribution. We examined the effect of acute mu-opioid agonist (remifentanil) administration on functional connectivity in BOLD FMRI signals. Functional connectivity (temporal covariation of BOLD signal) was increased between brainstem and anterior cingulate/insular cortex consistent with an influence of higher cortical centres on the pain-control regions of the brainstem. Conversely functional connectivity between basal ganglia (putamen) and sensorimotor cortex was reduced, a potential reflection of the drugs sedative effects.