Effect of propofol on the medial temporal lobe emotional memory system: a functional magnetic resonance imaging study in human subjects  K.O. Pryor, J.C. Root, M. Mehta, E. Stern, H. Pan, R.A. Veselis, D.A. Silbersweig  British Journal of Anaesthesia  Volume 115, Pages i104-i113 (July 2015) DOI: 10.1093/bja/aev038 Copyright © 2015 The Author(s) Terms and Conditions

Fig 1 Experimental paradigm. The middle line of the figure depicts the experimental sequence, and the bottom line the timing of the drug infusion. The top section shows segments of the experimental tasks in fine detail. The encoding task was performed in the scanner during the drug infusion. A sequence of 160 IAPS pictures was presented in 8 blocks of 20 items (purple bars), with 40 negative—arousing and 40 neutral images each shown twice as part of an old/new continuous recognition task. The recognition task was performed 120 min later outside of the scanner. Here, the 80 images previously seen in the encoding task and 80 novel images were shown in a random sequence across two blocks (blue bars). British Journal of Anaesthesia 2015 115, i104-i113DOI: (10.1093/bja/aev038) Copyright © 2015 The Author(s) Terms and Conditions

Fig 2 Exploratory assessment of whole-brain changes in the pattern of blood-oxygen-level-dependent (BOLD) activation. Whole-brain contrasts are shown at the exploratory visualization thresholds of uncorrected P<0.001 (column A), and uncorrected P<0.05 (column B). The contrast includes all stimuli and is undifferentiated with regard to the cognitive task. Regions in which propofol has a relative increase in BOLD signal are shown in orange, while regions with a relative decrease are shown in blue. The sagittal, coronal, and axial images represent plane views at Montreal Neurologic Institute co-ordinates x=0, y=0, and z=0. British Journal of Anaesthesia 2015 115, i104-i113DOI: (10.1093/bja/aev038) Copyright © 2015 The Author(s) Terms and Conditions

Fig 3 Response to emotional dynamics. Contrast between exposure to negative—arousing items and neutral items. Three coronal slices through the hippocampus (y-co-ordinates −36, −33, −30) and amygdala (0, 3, 6) are selected. (a) is placebo, and (b) propofol. Propofol had no effect on the amygdala response to emotional arousal, but markedly attenuated the hippocampal response. The scale shows color rendering of the groupwise t values, with yellows positive and blues negative. The threshold for color rendering is |t| ≥3.37. British Journal of Anaesthesia 2015 115, i104-i113DOI: (10.1093/bja/aev038) Copyright © 2015 The Author(s) Terms and Conditions

Fig 4 Hippocampal predictors of propofol amnesia. Rendering of a regression model correlating d′ with activation in the propofol condition. The analysis combines first and second image presentations. (a) Left parasagittal slice in the plane x=−12; (b) Right parasagittal slice in the plane x=18; (c) Coronal slice in the plane y=−36; (d) Relationship between d′ and the blood-oxygen-level-dependent (BOLD) signal extracted from the peak voxel in the left (blue) and right (red) hippocampus. Scale shows color rendering of the groupwise t values. The threshold for color rendering is |t| ≥3.37. Automated Anatomical Labeling masks for the hippocampus are indicated by the white line. British Journal of Anaesthesia 2015 115, i104-i113DOI: (10.1093/bja/aev038) Copyright © 2015 The Author(s) Terms and Conditions