5Fields HL,Basbaum Al.Central nervous system mechanism of pain modulation.In:Wall PD,Melzack R (eds) Textbook of pain.Churchill Livingstone,New York,1994.243-257.
7Price DD,Craggs J,Verne GN,et al.Placebo analgesia is accompanied by large reductions in pain-related brain activity in irritable bowel syndrome patients.Pain,2007,127(1-2):63-72.
8Willoch F,Tolle TR,Wester HJ,et al.Central pain after pontine infarction is associated with changes in opioid receptor binding:a PET study with 11C-diprenorphine.AJNR Am J Neuroradiol,1999,20(4):686-690.
9Willoch F,Schindler F,Wester HJ,et al.Central poststroke pain and reduced opioid receptor binding within pain processing circuitries:a[11C] diprenorphine PET study.Pain,2004,108 (3):213-220.
10Kong J,Gollub RL,Rosman IS,et al.Brain activity with expectancy-enhanced placebo analgesia as measured by functional magnetic resonance imaging.J Neurosci,2006,26(2):381-388.
