Functional Brain Imaging of Pain Phenotype and Genotype

University of Pittsburgh15 enrolled

Overview

This study has two purposes: first, to locate and identify the "brain activation" (the areas of the brain) which respond to pain; and second, to look at how brain activation is influenced by a person's genetics (the traits they inherited from their parents). A Magnetic Resonance Imaging (MRI) scanner will be used to gather pictures of the brain (similar to an x-ray, but based on different scientific principles) that will be used to determine which areas are active. The hypothesis is that the variation in brain activity between people can be partially explained by genetic differences. This study consists of an two pain tasks applied during a one time visit to the MRI suite. There are no followup visits.

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Pain

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age 18 to 50 * Right-handed * Male or female * Healthy individuals not taking any medication. Exclusion Criteria: * Pregnancy * Diagnosed with any treated or untreated medical or neurological conditions * Using any prescription drugs, including antidepressants, pain medications, sedative medications, blood pressure medications, seizure medications, or antipsychotics. Oral contraceptives are permitted * Using any over-the-counter medications including aspirin, Tylenol, or herbal supplements * Using any illicit substances * Contraindications to magnetic resonance imaging.

Outcomes

Primary Outcomes

Areas of brain activity from a transcutaneous painful stimulation

A nerve stimulator will be turned on at the level that causes you to report 7/10 pain for 30 seconds, followed by a 30 second period of rest. This will be repeated four times. The areas of brain activity are determined at the end of the 1 hour scanning session by analyzing the brain images. There are no additional followup or long term outcomes.

Time frame: At the conclusion of the 1 hour scanning session; Visit one

Areas of brain activity from a 45 minutes Capsaicin cream application

The painful stimulation will now be caused by placing a piece of gauze soaked with capsaicin, the active ingredients in chili peppers, on the subject's right arm. The areas of brain activity are determined at the end of the 1 hour scanning session by analyzing the brain images. There are no additional followup or long term outcomes.

Time frame: At the conclusion of the 1 hour scanning session; Visit 1

Secondary Outcomes

Pain phenotyping

Subjects will report their pain at least every 3 minutes during the cream application. The subject's pain phenotype will be determined from this response.

Time frame: After the 45 minute Capsaicin cream application; Visit 1