TY - JOUR
T1 - The Effect of Oral Morphine on Pain-Related Brain Activation - An Experimental Functional Magnetic Resonance Imaging Study
AU - Hansen, Tine Maria
AU - Olesen, Anne Estrup
AU - Graversen, Carina
AU - Drewes, Asbjørn Mohr
AU - Frøkjaer, Jens Brøndum
N1 - This article is protected by copyright. All rights reserved.
PY - 2015
Y1 - 2015
N2 - Knowledge about cerebral mechanisms underlying pain perception and effect of analgesic drugs is important for developing methods for diagnosis and treatment of pain. The aim was to explore altered brain activation before and after morphine treatment using functional magnetic resonance imaging recorded during experimental painful heat stimulation. Functional magnetic resonance imaging data were recorded and analysed in 20 healthy volunteers (13 males and 7 females, 24.9±2.6 years) in a randomised, double-blind, placebo-controlled, cross-over study. Painful stimulations were applied to the right forearm using a Contact Heat Evoked Potential Stimulator (CHEPS) before and after treatment with 30 mg oral morphine and placebo. CHEPS stimulations before treatment induced activation in the anterior cingulate cortex, secondary somatosensory cortex/insula, thalamus and cerebellum (n=16, p<0.05). In response to morphine treatment, the spatial extent of these pain-specific areas decreased (n=20). Reduced pain-induced activation was seen in the right insula, anterior cingulate cortex and inferior parietal cortex after morphine treatment compared to before treatment (n=16, p<0.05) and sensory ratings of pain perception were significantly reduced after morphine treatment (p=0.02). No effect on pain-induced brain activation was seen after placebo treatment compared to before treatment (n=12, p>0.05). In conclusion, heat stimulation activated areas in the "pain matrix" and a clinically relevant dose of orally administered morphine revealed significant changes in brain areas where opioidergic pathways are predominant. The method may be useful to investigate mechanisms of analgesics. This article is protected by copyright. All rights reserved.
AB - Knowledge about cerebral mechanisms underlying pain perception and effect of analgesic drugs is important for developing methods for diagnosis and treatment of pain. The aim was to explore altered brain activation before and after morphine treatment using functional magnetic resonance imaging recorded during experimental painful heat stimulation. Functional magnetic resonance imaging data were recorded and analysed in 20 healthy volunteers (13 males and 7 females, 24.9±2.6 years) in a randomised, double-blind, placebo-controlled, cross-over study. Painful stimulations were applied to the right forearm using a Contact Heat Evoked Potential Stimulator (CHEPS) before and after treatment with 30 mg oral morphine and placebo. CHEPS stimulations before treatment induced activation in the anterior cingulate cortex, secondary somatosensory cortex/insula, thalamus and cerebellum (n=16, p<0.05). In response to morphine treatment, the spatial extent of these pain-specific areas decreased (n=20). Reduced pain-induced activation was seen in the right insula, anterior cingulate cortex and inferior parietal cortex after morphine treatment compared to before treatment (n=16, p<0.05) and sensory ratings of pain perception were significantly reduced after morphine treatment (p=0.02). No effect on pain-induced brain activation was seen after placebo treatment compared to before treatment (n=12, p>0.05). In conclusion, heat stimulation activated areas in the "pain matrix" and a clinically relevant dose of orally administered morphine revealed significant changes in brain areas where opioidergic pathways are predominant. The method may be useful to investigate mechanisms of analgesics. This article is protected by copyright. All rights reserved.
U2 - 10.1111/bcpt.12415
DO - 10.1111/bcpt.12415
M3 - Journal article
C2 - 25924691
SN - 1742-7835
VL - 117
SP - 316
EP - 322
JO - Basic & Clinical Pharmacology & Toxicology
JF - Basic & Clinical Pharmacology & Toxicology
IS - 5
ER -