Glymphatic System, Neurodegeneration
Conditions
Keywords
glymphatic system, cerebral perfusion, aerobic exercise
Brief summary
This study investigates changes in glymphatic flow in the brain acutely after vigorous-intensity steady-state aerobic exercise. Twenty subjects (10 male and 10 female) perform 25 minute submaximal cycle ergometry exercise and the changes in the glymphatic flow and cerebral perfusion are evaluated using a variety of MRI sequences (e.g. MREG).
Detailed description
The glymphatic system is a drainage system for the brain to help maintain fluid balance and extract waste metabolites. Glymphatic system function (healthy glymphatic flow) may prevent accumulation of harmful substances and therefore slow down the onset of neurodegenerative diseases. The hypothesis is, that glymphatic flow could be increased through exercise and enhanced cerebral arterial pulsality, which might explain some of the brain health benefits of exercise proven in epidemiological studies. This study indirectly investigates the acute changes in the glymphatic flow acutely after aerobic exercise using MREG that measures pulse wave propagation as an indirect surrogate marker for glymphatic flow. Twenty healthy subjects (n=20, 10 male, 10 female, age 18-45 years) will perform 25 minute 70%VO2max cycle ergometry exercise. The glymphatic flow and cerebral perfusion will be measured using magnetic resonance imaging sequences before and after exercise. The glymphatic flow is measured using 10 Hz fMRI technique called magnetic resonance encephalography (MREG). In addition, perfusion MRI is used to evaluate changes in brain perfusion.
Interventions
25 minutes, 70% VO2max steady state cycle ergometry exercise
Sponsors
Turku University Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Prospective interventional study model, all subjects undergo the same exercise intervention and results are compared to baseline values
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18-45 * BMI 18-30 * Resting Blood pressure \< 140/90 mmHg
Exclusion criteria
* History of a cardiac event * Insulin or medically treated diabetes * Any chronic disease or condition that could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results * Presence of ferromagnetic objects that would make MR imaging contraindicated * Claustrophobia * Abundant use of alcohol * Use of narcotics * Smoking of tobacco or consuming snuff tobacco * Diagnosed depressive or bipolar disorder * Abnormalities in resting ECG (revised by the study physician) * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| MREG cardiovascular pulse wavefront | 3 hours | Is processed into three-dimensional vector fields and used as an assessment of glymphatic flow, scanned once before and multiple times after exercise intervention in 5-minute sequences |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cerebral perfusion fMRI | 3 hours | 5-minute MR imaging sequences evaluating changes in blood flow, scanned once before and multiple times after exercise intervention |
| Heart rate (HR) | 3 hours | Wearable heart rate monitoring, measures heart beats per second, continuous throughout the study |
| Blood pressure (BP) | 3 hours | Blood pressure monitoring, evaluates systolic and diastolic pressures (mmHg) continuous throughout the study |
Countries
Finland
Contacts
Primary ContactIlkka Heinonen, PhD
Outcome results
None listed