A mice resting-state functional magnetic resonance imaging dataset on the effects of medetomidine dosages and prior-stimulation on functional connectivity

Abstract

Nine 8 C57Bl6 mice (9 ± 0.5 months) were utilised for this dataset. Each animal was scanned twice on a 9.4T Bruker Magnetic Resonance Imaging (MRI) scanner using a cryogenically cooled coil with 0.1 mg/kg body weight/h (low) or 0.3 mg/kg body weight/h (high) medetomidine doses; 0.5% isoflurane was used in conjunction with both doses. The scans were one week apart, and the first session's dose was decided randomly. In each session, the animal had a pre-stimulation resting-state functional Magnetic Resonance Imaging (rs-fMRI) scan followed by 10 min where mild, constant electrical stimulation to the forepaw was applied, and a post-stimulation rs-fMRI scan. Each fMRI scan lasted 10 min, and there was 5 min break between fMRI scans. The dataset included, for each animal, a pair of forward-phase and reverse-phase gradient echo Echo-Planar-Imaging (EPI) images for EPI distortion correction purpose and three (unprocessed) functional MRI images acquired using the same EPI sequence: prior, during, and post-stimulation. The MRI data was saved in compressed NIFTI format converted from Bruker DICOMs. The dataset also included the pre-processed functional MRI images, with the following pre-processing steps: slice-timing correction, temporal despiking, motion correction, distortion correction, band-pass filtration at 0.01-0.2 Hz, and spatial normalisation. This dataset adds to the publicly available collection of resting-state functional MRI in the mice and facilitates reproducibility and validation of functional imaging and its analysis.

Keywords: Electrical stimulation; Functional connectivity; MRI; Magnetic Resonance Imaging; Medetomidine; Resting state.

Fig. 1

Summarised spatial maps of the ``signal'' components from the Independent Vector Analysis of the functional Magnetic Resonance Imaging data, grouped into eight networks/anatomical groupings, namely the Anterior Cingulate – Retrosplenial areas axis (ACA – RSN), the Visual and Auditory areas (VA), the Hippocampal – Subcortical memory circuit (HP – MEM), the Primary Somatosensory areas (S1), the Striatum (STR), the Motor areas (MO), the Salience Network (SN), and the Supplementary Somatosensory areas (S2).

Fig. 2

Calculated functional connectivity among the ``signal'' independent components shown in Fig. 1 under 0.3 mg/kg/h medetomidine dose after constant mild electrical stimulation to the forepaw (for how this was generated, see Experimental design, materials, and methods.). Functional connectivity matrix was generated using one sample t-test, corrected for multiple comparison correction using permutation-based test and False Discovery Rate, and thresholded at Q < 0.05. Matrix’s colours were scaled using the Z test statistics. Red–Yellow cells: positive correlation. Blue–Green cells: negative correlation.