Fig. 1: Functional ultrasound imaging of intravenous ketamine administration.
From: Sex dependence of opioid-mediated responses to subanesthetic ketamine in rats
a Schematic representation of the imaging setup. A surgical craniotomy enables ultrasound penetration, and an implanted chronic prosthesis allows imaging over repeated sessions. Drawing created in BioRender. b Coronal slices of the rat brain were imaged at bregma +2.5 mm and bregma −3.5 mm. The segmented regions of interest (ROIs) are highlighted on the Paxinos & Watson rat brain atlas30. c Sequence of cerebral blood volume (CBV) coronal maps at bregma +2.5 mm and bregma −3.5 mm following administration of 10 mg/kg i.v. ketamine. The pixel intensity shows the CBV signals as a normalized difference with a pre-injection baseline (10 min). The time axis was zeroed at the time of ketamine injection. d The coronal maps were segmented and the CBV signals were averaged in the relevant ROIs. The plots show CBV time series in response to increasing doses of i.v. ketamine. Solid lines represent the mean values and shaded areas are SEM from n = 9 rats/group (10 and 5 mg/kg) or n = 8 rats/group (1 and 0 mg/kg). e Peak CBV in the segmented ROIs. Two-way mixed-effects ANOVA; within-subjects factor of region, F3.08,92.55 = 17.82, P = 2.33E-09; between-subjects factor of dose, F3,30 = 8.26, P = 3.74E-04; interaction, F9.25,92.55 = 3.38, P = 0.001. Two-tailed unpaired t-test, *corrected P < 0.05; **P < 0.01; ***P < 0.001. n = 9 rats/group (10 and 5 mg/kg); n = 8 rats/group (1 and 0 mg/kg). Data are presented as mean +/− SEM. Source data are provided as a Source Data file. Details on the statistical analyses are provided in Supplementary Table 1. KET: ketamine. Cg1 cingulate area 1, PrL prelimbic cortex, IL infralimbic cortex, M2 secondary motor cortex, M1 primary motor cortex, S1 primary somatosensory cortex, Ins insular cortex, CPu caudate putamen, NAcC nucleus accumbens core, NAcSh nucleus accumbens shell, LPtA lateral parietal association cortex, MPtA medial parietal association cortex, RSG granular retrosplenial cortex, RSD dysgranular retrosplenial cortex, Hipp hippocampus, LHb lateral habenula, LPLR lateral posterior thalamic nucleus, VM ventromedial thalamic nucleus, VPM ventral posteromedial thalamic nucleus, VPL ventral posterolateral thalamic nucleus.
