Magnetic Resonance Imaging of the Effect of Music Listening on Brain Activity Under Anesthesia

Study Overview
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Brief Summary
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This study is to better understand the systems-level neuronal mechanisms by which general anesthetics produce loss of consciousness.The researchers believe that anesthetics suppress consciousness by disrupting the functioning of large-scale brain networks that support information integration in the brain.

Official Title
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Magnetic Resonance Imaging of the Effect of Music Listening on Brain Activity Under Anesthesia

Conditions
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Healthy

Intervention / Treatment
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* Other: Functional Magnetic Resonance Imaging (fMRI)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologist physical status of 1 (ASA-1), Healthy, non-smoking, no or minimal alcohol use Right-handed Body mass index (BMI) of less than 30 English speakers Exclusion Criteria: Medical contraindication to Magnetic Resonance Imaging (MRI) scanning Unable to undergo MRI scanning because of possible pregnancy BMI over 30 Tattoos in the head or neck region Unwilling to abstain from alcohol for 24 hours prior to dosing

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Functional Magnetic Resonance Imaging<br>While music is played Noninvasive functional magnetic resonance (fMRI) imaging will be performed at the University of Michigan Health System, University Hospital, Department of Radiology. The fMRI is done under anesthesia using propofol. The researchers will manually control the infusion of propofol to achieve target effect-site concentrations of 1.2, 1.6, 2.0, and 2.4 μg/ml in a stepwise fashion. | Other: Functional Magnetic Resonance Imaging (fMRI)<br>* Propofol will be administered by intravenous infusion. All anesthesia equipment, supplies, and drugs will be provided by anesthesiologists from the University of Michigan Health System. The researchers will manually control the infusion of propofol to achieve target effect-site concentrations which will be maintained for 4 minutes each. Four types of music, including Jazz, Rock, Pop and Country, will be presented in a pseudo-randomized order. During the behavioral test period, participants will be asked to squeeze an Magnetic Resonance Imaging (MRI) compatible grip dynamometer (a rubber ball) for every 10-second periods (96 cycles in total). The beginning of each cycle will be cued with the spoken word squeeze.<br>* Other names: Diprivan;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Oxygen Level Dependent (BOLD) Response to Sensory Stimuli During Sedation | Music evoked activity was quantified by measurements of the fMRI BOLD signal. Neural response to a natural auditory stimulus, music, was assessed during both conscious and anesthetized states. Measurements were taken at baseline (30 minutes) and during anesthesia (60 minutes). | 60 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Squeeze Pressure Over 60 Minutes | Measurement of force of participants' hand squeezing on a rubber ball in response to instructions. This will be measured in millimeters of mercury (mmHg) of air pressure during squeezing the rubber ball. Measurements are provided for the 30-minute means based on measurements taken every 10 seconds for 30 minutes prior to intervention (baseline) and every 10 seconds for 30 minutes during intervention (intervention), using BIOPAC (https://www.biopac.com) MP160 system with AcqKnowledge software (V5.0). | 60 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Music, Propofol