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Magnetic Resonance ImagingPhase 2NCT06629090

Brain Blood Vessel Responses to Changes in Blood Flow: Younger Cohort

A Phase 2 study testing MRI and Prazosin in people with Magnetic Resonance Imaging and Cerebrovascular Circulation, run by University of Wisconsin, Madison at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging. Read more about this study

Who is it for?
Ages 20 to 40 yearsHealthy volunteers can take part
What is being tested?
MRI and Prazosin
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
36 participants
Where
1 siteUnited States
Study dates
17 Dec 2025to May 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Between the ages of 20-40 years
  • Have a BMI ≤34.5 kg/m2
  • are less than 72 in (182.88 cm) height
  • Nonsmoker

Who cannot join

  • Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)
  • History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis
  • History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia
  • Uncontrolled hypertension
  • History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease
  • Severe untreated obstructive sleep apnea
Show all 15Show fewer
  • History of diabetes with HbA1c greater than 9.5 percent
  • Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)
  • Current or recent (less than1 year) major psychiatric condition (Axis I) or addictive disorders
  • Significant surgical history
  • Other significant medical conditions at investigators' discretion
  • Contraindications to MRI
  • Prescribed medications that interfere with prazosin
  • Lactose allergy
  • lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI)

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Anna Howery contact

608-262-9572

ahowery@wisc.edu

United States1 site, 1 recruiting
  • University of Wisconsin

    Madison, Wisconsin, 53705

    Anna J Howery, MS, 608-262-9572, barneslab@education.wisc.edu

    Jill N Barnes, PhD

    Recruiting

Other trials in United States

About this study

Official title: Cerebrovascular Responses to Acute Hypoperfusion

Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.

Read the detailed description

Global cerebral blood flow (CBF) decreases with advancing age; however, some adults have accelerated declines in CBF, placing them at a greater risk of cognitive impairment. However, there is a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. This study will systematically address this gap in knowledge by examining cerebrovascular control in adults during acute physiological challenges (simulated postural change test and breathing increased carbon dioxide) that stimulate a change in CBF.

Being tested
MRI, Prazosin, Placebo
Keywords
Magnetic Resonance Imaging, Brain Blood Flow, Lower Body Negative Pressure, Carbon Dioxide

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • MRIDevice

    Participants will undergo an MRI scan while performing breathing and simulated postural change tasks.

  • PrazosinDrug

    A dose of prazosin will be administered based on body weight

  • PlaceboDrug

    Oral placebo

Study groups in NCT06629090
Study groupRoleWhat they receive
Young AdultsExperimentalYoung Adults between 20-40 years of age.
Receives: Device: MRI; Drug: Prazosin; Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in blood velocity

    The change in blood velocity during breathing and simulated postural change tasks will be measured with MRI

    Measured: Two study visits, up to 240 minutes

  2. Change in blood flow

    The change in intracranial blood flow during breathing and simulated postural change tasks will be measured with MRI

    Measured: Two study visits, up to 240 minutes

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Oct 2024
  2. Study start17 Dec 2025
  3. Primary completionMay 2027 (estimated)
  4. Study completionMay 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
36 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06629090
Sponsor's protocol ID
2024-0377: Younger Cohort
Other IDs
A176000, EDUC/KINESIOLOGY, Protocol Version 7/29/2025
Status last verified
Jul 2026
First submitted
4 Oct 2024
Last updated
6 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing MRI and Prazosin in people with Magnetic Resonance Imaging and Cerebrovascular Circulation, run by University of Wisconsin, Madison at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 6 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Anna Howery (608-262-9572, ahowery@wisc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in blood velocity (time frame: Two study visits, up to 240 minutes). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Jul 2026.

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