The Influence of Pressure Pain on [11C]Diprenorphine Binding Potentials

Inclusion Criteria:

• Healthy male and female adults, 21 to 50 years of age
• No contraindications to fMRI and PET scanning
• Within 15% of ideal body mass index (BMI)

Exclusion Criteria:

• Current significant medical, neurological, or psychiatric illness as assessed by the Physician Investigators
• Women who are pregnant or breast feeding, have gone through menopause, and/or have irregular menstrual cycles
• Claustrophobia
• History of head trauma
• Instability of responses to experimental pain (See Study Procedure Section Part II)
• History of asthma
• Use of psychotropic drugs or hormone treatments (including hormonal birth control) within one year of date of consent
• History of smoking
• Routine exercise in excess of one hour per day and/or three times per week
• Non-fluent English speaker