720 mt m gradient system

MR measurements were acquired using a 9.4 T Bruker Biospec 94/20 small animal scanner equipped with a 720 mT/m gradient system (Bruker BioSpin GmbH, Ettlingen, Germany) and different combinations of transmit coils and receive-only coils. First, an anatomical image was acquired to identify the slice position for fMRI measurements: 2D Turbo spin echo sequence (RARE), TR/TE_Eff = 2,000/50 ms, RARE factor 8, Matrix 256 × 256, field of view (FOV) 28 mm × 26 mm, slice thickness 1.2 mm, 9–12 contiguous slices. Subsequently, B₀ homogenization was performed using the MAPSHIM Bruker routine. Functional GE-EPI and SE-EPI measurements were performed using a single-shot EPI sequence (same FOV as anatomy, Matrix: 80 × 80, 1.2 mm slice thickness; GE-EPI: TE 18 ms, TR 100/125/1,000 ms, flip angle 18/21/60 or 65°, 1/2/9 or 12 slices; SE-EPI: TE 35.9 ms, TR 250 ms, flip angle 90°, 3 slices). One fMRI measurement lasted between 5 and 25 min (Supplementary Table 1).

All MR measurements were acquired on a 9.4 T Bruker Biospec 94/20 small animal scanner equipped with a $720\mathrm{mT}/\mathrm{m}$ gradient system (Bruker BioSpin GmbH, Ettlingen, Germany), a linearly polarized resonator, and a receive-only surface coil with 2 cm (MRI) or 1 cm (MRS) diameter. First, an anatomical image was acquired to identify the slice position for echo-planar imaging (EPI) or the voxel position for spectroscopy: 2D Turbo spin echo sequence (RARE), $\mathrm{TR}/{\mathrm{TE}}_{\mathrm{Eff}}=2000/50\mathrm{ms}$ , RARE factor 8, Matrix $256\times 256$ , field of view (FOV) $28\times 26{\mathrm{mm}}^2$ , slice thickness 1.2 mm, nine contiguous slices. Subsequently, $B_0$ homogenization in the area of interest was achieved using the MAPSHIM Bruker routine.