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HealthyPhase 4AmygdalaNCT00504894

Neuroimaging the Effects of Intravenous Anesthetic on Amygdala Dependent Memory Processes

A Phase 4 study testing Propofol and Thiopental in people with Healthy, run by Weill Medical College of Cornell University at 1 site in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

This study involves 60 healthy volunteers aged between 18 and 50 recruited from the general community. It involves doing a set of simple memory tests while inside a fMRI machine. The subject is given a very low dose of an anesthetic drug intravenously while in the scanner. Read more about this study

Who is it for?
Ages 18 to 50 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Propofol and Thiopental
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
60 participants
Where
1 siteUnited States
Study dates
Mar 2007to Nov 2013
Phase
Phase 4
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 18 to 50 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • age b/w 18 and 50
  • right-handed
  • minimum of high school education
  • fluent in English
  • normal vocabulary

Who cannot join

  • any significant medical/psychiatric comorbidity
  • deficit in vision or hearing that would impede the study
  • allergies to any of the study drugs, to soybeans, or eggs.
  • history of head trauma
  • family history of major psychiatric illness
  • body mass index > 30 kg/m2
Show all 11Show fewer
  • claustrophobia
  • prior exposure to IAPS pictures
  • pregnancy
  • permanent metal objects anywhere in the body
  • a personal/family history of any porphyria

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Weill Cornell Medical College

    New York, New York, 10065

Other trials in United States

About this study

This study involves 60 healthy volunteers aged between 18 and 50 recruited from the general community. It involves doing a set of simple memory tests while inside a fMRI machine. The subject is given a very low dose of an anesthetic drug intravenously while in the scanner. The subject then sees a sequence of pictures on a screen, and presses a button if they remember seeing the picture before. While this is happening, the scanner will be capturing images that tell us what parts of the brain are active. Hypothesis: patterns of hippocampal and amygdala activation during the encoding and retrieval of memory,as measured by fMRI, will be altered by intravenous anesthetics such that suppression of hippocampal and amygdala activities will be dissociable. This dissociation pattern will be different between the drugs propofol and thiopental.

Read the detailed description

Background: Subclinical doses of propofol produce anterograde amnesia, characterized by an early failure of memory consolidation. It is unknown how propofol affects the amygdala-dependent emotional memory system, which modulates consolidation in the hippocampus in response to emotional arousal and neurohumoral stress. We present an event-related functional magnetic resonance imaging study of the effects of propofol on the emotional memory system in human subjects.

Methods: Sixty healthy subjects were randomized to receive propofol, at an estimated brain concentration of 0.90 μgml-1, thiopental, at an estimated brain concentration of 3.0 μgml-1, or placebo. During drug infusion, emotionally arousing and neutral images were presented in a continuous recognition task, while blood-oxygen-level-dependent activation responses were acquired. After a drug-free interval of 2 h, subsequent memory for successfully encoded items was assessed. Imaging analysis was performed using statistical parametric mapping and behavioural analysis using signal detection models.

Conditions
Healthy
Being tested
Placebo, Propofol, Thiopental
Keywords
N/A healthy volunteers

What participants receive

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

  • PlaceboDrug

    A low dose given intravenously one time for just under an hour while the subject is shown visually stimulating images in an MRI machine.

  • PropofolDrug

    A low dose of propofol 0.90 μgml-1, given intravenously while the subject is shown visually stimulating images in an MRI machine.

  • ThiopentalDrug

    A low dose of thiopental 3.0 μgml-1, given intravenously while the subject is shown visually stimulating images in an MRI machine.

Study groups in NCT00504894
Study groupRoleWhat they receive
PlaceboPlacebo comparatorPlacebo given in low dose to gauge subject's responses to visual stimuli.
Receives: Drug: Placebo
PropofolActive comparatorPropofol given at 0.90 μgml-1 to gauge subject's responses to visual stimuli.
Receives: Drug: Propofol
ThiopentalActive comparatorThiopental given at 3.0 μgml-1 to gauge subject's responses to visual stimuli.
Receives: Drug: Thiopental

What is being measured

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

  1. Blood-oxygen-level-dependent Significant Activation Cluster

    Three anatomical regions for which there was an a priori mechanistic hypothesis were assessed using standard small volume correction: (i) the amygdala, bilaterally; (ii) the hippocampus, bilaterally; and (iii) the parahippocampus, bilaterally. Using single-tailed t tests, a priori regions were reported as significant if the initial uncorrected voxel-wise P value was < 0.001, and then the P value was < 0.05 after family-wise error correction for multiple comparisons in the hypothesized anatomical region. For non-hypothesized regions outside the medial temporal lobe, findings were reported as significant if the initial uncorrected voxel-wise P value was < 0.001, and then the P value was < 0.05 after family-wise error correction for multiple comparisons across the whole brain. Clusters containing voxel maxima at these thresholds are reported.

    Measured: for 90 minutes after the drug/placebo was commenced

Secondary outcomes (1)
  1. Blood-oxygen-level-dependent Significant Activation Cluster for Positive Sequential Memory

    Three anatomical regions for which there was an a priori mechanistic hypothesis were assessed using standard small volume correction: (i) the amygdala, bilaterally; (ii) the hippocampus, bilaterally; and (iii) the parahippocampus, bilaterally. Using single-tailed t tests, a priori regions were reported as significant if the initial uncorrected voxel-wise P value was < 0.001, and then the P value was < 0.05 after family-wise error correction for multiple comparisons in the hypothesized anatomical region. For non-hypothesized regions outside the medial temporal lobe, findings were reported as significant if the initial uncorrected voxel-wise P value was < 0.001, and then the P value was < 0.05 after family-wise error correction for multiple comparisons across the whole brain. Clusters containing voxel maxima at these thresholds are reported.

    Measured: for 90 minutes after the drug/placebo was commenced

Timeline

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

  1. First posted20 Jul 2007 (estimated)
  2. Study startMar 2007
  3. Primary completionNov 2013
  4. Study completionNov 2013

Why it stopped: One study drug (thiopental) became commercially unavailable

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 4
Primary purpose
Other
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
60 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00504894
Sponsor's protocol ID
0701008933
Other IDs
K08GM083213
Acronym
Amygdala
Status last verified
Jun 2021
First submitted
19 Jul 2007
Last updated
15 Jul 2021
Data monitoring committee
No
Individual data sharing
No

Publications

  • Pryor KO, Root JC, Mehta M, Stern E, Pan H, Veselis RA, Silbersweig DA. Effect of propofol on the medial temporal lobe emotional memory system: a functional magnetic resonance imaging study in human subjects. Br J Anaesth. 2015 Jul;115 Suppl 1(Suppl 1):i104-i113. doi: 10.1093/bja/aev038.

    PubMed 26174294

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Propofol and Thiopental in people with Healthy, run by Weill Medical College of Cornell University 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 5 inclusion and 11 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: stopped early, as of the sponsor's last update on 15 Jul 2021. 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. Some participants in this study may receive a placebo. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

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

Are results available for this study?

Yes. Results are posted in the registry (first posted 18 May 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Blood-oxygen-level-dependent Significant Activation Cluster (time frame: for 90 minutes after the drug/placebo was commenced). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00504894, which also lists 1 linked publication.

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 15 Jul 2021.

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