Effect of propofol on the medial temporal lobe emotional memory system: A functional magnetic resonance imaging study in human subjects Journal Article
| Authors: | Pryor, K. O.; Root, J. C.; Mehta, M.; Stern, E.; Pan, H.; Veselis, R. A.; Silbersweig, D. A. |
| Article Title: | Effect of propofol on the medial temporal lobe emotional memory system: A functional magnetic resonance imaging study in human subjects |
| Abstract: | 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: Thirty-five healthy subjectswere randomized to receive propofol, at an estimated brain concentration of 0.90 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. Results: Propofol had no effect on the stereotypical amygdalar response to emotional arousal, but caused marked suppression of the hippocampal response. Propofol caused memory performance to become uncoupled from amygdalar activation, but it remained correlated with activation in the posterior hippocampus, which decreased in proportion to amnesia. Conclusions: Propofol is relatively ineffective at suppressing amygdalar activation at sedative doses, but abolishes emotional modulation and causes amnesia via mechanisms that commonly involve hyporesponsiveness of the hippocampus. These findings raise the possibility that amygdala-dependent fear systems may remain intact even when a patient has diminished memory of events. This may be of clinical importance in the perioperative development of fear-based psychopathologies, such as post-Traumatic stress disorder. © 2015 The Author . Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. |
| Keywords: | adult; controlled study; randomized controlled trial; propofol; body mass; drug infusion; posttraumatic stress disorder; emotion; blood pressure; memory; fmri; functional magnetic resonance imaging; recognition; amnesia; signal detection; oxygen saturation; normal human; pharmacology; human experiment; nuclear magnetic resonance scanner; memory consolidation; reaction time; hippocampus; amygdala; echo planar imaging; arousal; bold signal; amygdaloid nucleus; drug brain level; drug effects; primary motor cortex; state trait anxiety inventory; executive function; blood vessel reactivity; human; male; female; priority journal; article; chemically induced; brain analysis; frontal operculum; medial temporal lobe; postcentral gyrus |
| Journal Title: | British Journal of Anaesthesia |
| Volume: | 115 |
| Issue: | Suppl. 1 |
| ISSN: | 0007-0912 |
| Publisher: | Oxford University Press |
| Date Published: | 2015-07-01 |
| Start Page: | i104 |
| End Page: | i113 |
| Language: | English |
| DOI: | 10.1093/bja/aev038 |
| PROVIDER: | scopus |
| PMCID: | PMC4501915 |
| PUBMED: | 26174294 |
| DOI/URL: | |
| Notes: | Export Date: 2 October 2015 -- Source: Scopus |
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