Clinical trial NCT00504894: Neuroimaging the Effects of Intravenous Anesthetic on Amygdala Dependent Memory Processes
Official title: Neuroimaging the Effects of Intravenous Anesthetic on Amygdala Dependent Memory Processes
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: PHASE4
Conditions: Healthy
Keywords: N/A healthy volunteers
Lead sponsor: Weill Medical College of Cornell University
Sponsor class: OTHER
Collaborators: name: National Institutes of Health (NIH)
name: National Institute of General Medical Sciences (NIGMS)
First posted: 2007-07-20
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief 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. 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.

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.

Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

* 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
* claustrophobia
* prior exposure to IAPS pictures
* pregnancy
* permanent metal objects anywhere in the body
* a personal/family history of any porphyria

Primary outcomes:
measure: Blood-oxygen-level-dependent Significant Activation Cluster
timeFrame: for 90 minutes after the drug/placebo was commenced
Secondary outcomes:
measure: Blood-oxygen-level-dependent Significant Activation Cluster for Positive Sequential Memory
timeFrame: for 90 minutes after the drug/placebo was commenced
Other outcomes:
Locations:
city: New York
country: United States
facility: Weill Cornell Medical College
state: New York
Study officials:
affiliation: Weill Medical College of Cornell University
name: Kane Pryor, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.