Healthy
Conditions
Keywords
Glymphatics, Cerebrospinal fluid
Brief summary
This study will perform magnetic resonance imaging (MRI) measurements of hemodynamics and cerebrospinal fluid flow across breathing tasks and during breath-locked neuromodulation.
Detailed description
Cerebrospinal fluid (CSF) flow is essential for brain health, as it clears waste products from the brain. This study will investigate how breathing affects the flow of CSF around the brain. The investigators will perform high resolution magnetic resonance imaging (MRI) scans in participants who are breathing in specific patterns or performing simple tasks and test the effects on CSF flow. Participants will complete an imaging study visit in which the investigators will image their brain activity while they perform simple tasks, including paced breathing tasks. The participants will be split into two arms: (1) paced breathing (25 participants low resolution, 15 participants high resolution), (2) transcutaneous vagal nerve stimulation (25 participants low resolution, 15 participants high resolution). The MRI scans will take place in the 7 Tesla MRI scanner at Massachusetts General Hospital.
Interventions
Noninvasive stimulation vs sham stimulation will be delivered via an auricular device.
BEHAVIORALBreathing task
Participants will be asked to breathe in specific patterns.
Sponsors
Boston University Charles River Campus
National Center for Complementary and Integrative Health (NCCIH)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Adult age 18-70 years
Exclusion criteria
* No ferrous metal implanted in head or body * No history of major head trauma * No neurological or psychiatric disorder * Not using medication that affects brain function * No implanted electronic devices (e.g. pacemaker) * No implant that poses an MR contraindication * Not pregnant, suspect they are pregnant, or seeking to become pregnant * Not claustrophobic * No piercings or jewelry that cannot be removed * Does not weigh more than 250 pounds * Normal or contact-corrected normal vision Exclusion for transcutaneous vagus nerve stimulation (tVNS) arm: * Conditions of skin or anatomy that affect left auricle or forehead skin and could impact placement of electrodes for tVNS or forehead stimulation * Diagnosis of significant cardiovascular or cerebrovascular disease \[e.g. congestive heart failure, stroke, cardiac conduction disorders (including: bundle branch block, heart block, long Q-T syndrome), history of asystole or non-sustained ventricular tachycardia. * Bradycardia (defined as resting heart rate \<50 bpm) * Hypotension defined as blood pressure \<90/60 mmHg
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| functional magnetic resonance imaging (fMRI) signals | During study (2 hours) | fMRI measures of hemodynamic responses. Units: percent signal change |
| Cerebrospinal fluid (CSF) signals | During study (2 hours) | MR-based measures of CSF signals. Units: percent signal change |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Heart rate | During study ( 2 hours) | Heart rate variability will be calculated. Units: milliseconds (ms) |
| Pulse oximetry | During study ( 2 hours) | Amplitude of pulse oximetry signal. Units: arbitrary (no physical units are output by this system) |
| Respiratory physiology timing | During study (2 hours) | Breath timing. Units: Hertz (Hz) |
| Respiratory physiology amplitude | During study (2 hours) | Breath amplitude. Units: arbitrary (no physical units output by this sensor) |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORLaura Lewis, PhD
Boston University
Outcome results
None listed