In vivo imaging of anaesthetic action in humans: Approaches with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI)

Abstract

In summary, the studies described above revealed parts of the neuroanatomical pathways that are important for the reduced intensity and response to pain after opioid and nitrous oxide application. Administration of opioids or nitrous oxide during painful stimulation caused deactivation in the thalamus and activation in the anterior cingulate cortex. These areas therefore appear to be targets for opioid and nitrous oxide analgesia. The observed differences in the pattern of rCBF activation caused by the analgesics further suggests that opioids and nitrous oxide modulate pain perception by affecting different neural circuits.