Pilot Study Evaluating Neuro-Imaging Correlates of Epigenetic Finding in Prediction of Chronic Postsurgical Pain

Inclusion Criteria: 1. Male or female aged ≥ 8 yrs of age 2. English speaking; 3. Healthy (Defined as American Society of Anesthesiologists Physical Status 1 or 2) 4. Ability to provide assent/consent/parent permission. 5. Scheduled to undergo chest surgery (thoracotomy, thoracoscopy, Nuss procedure, pectus surgery, mastectomy), spine surgery, amputation, hernia repair or hip/knee replacement. Exclusion Criteria: 1. History of chronic pain conditions including migraines 2. Use of opioids chronically or for major surgery within the 6 months prior to enrollment 3. Severe obesity (BMI\>35 kg/m2) 4. Taking no more than two concomitant medications known to induce or inhibit CYP2D6 activity, including paroxetine, fluoxetine, cimetidine, and duloxetine or other medications used to treat attention deficit hyperactivity disorder (medications containing amphetamine or methylphenidate). 5. Use of hormonal contraceptives 6. Use of medications that may alter pain sensitivity (e.g. gabapentin,/pregabalin amitryptiline/other antidepressants, clonidine). 7. Active or history of renal/liver problems or congenital cardiac disease 8. Diagnosed developmental delay 9. Pregnant or lactating females 10. Any skin condition that prevents cuff application 11. History of seizures 12. Claustrophobia 13. Metallic implants/orthodontics/braces or other MRI exclusion (MRI safety screening will be conducted prior to enrollment and prior to each MRI scan)