Fig. 1: Resting-state functional connectivity in chemically immobilized rats.

a Protocol for acclimation and imaging of chemically immobilized rats, showing the schedule of procedures over days (squares at the top) and the timing of individual acclimation sessions at the bottom. Catheter implantation (red shading, top) and blood draws (red arrowheads, bottom) were performed only on animals used for corticosterone monitoring. b Increase in relative corticosterone concentration (after/before treatment) induced by three successive sessions of acclimation to head restraint (gray, n = 4) or chemical immobilization (dark blue, n = 4) or during one session of mock treatment without immobilization stress (n = 7). c Motion parameters (maximal displacements dx, dy, and dz, all in mm) computed from fMRI data series measured using anesthetized rats (An, cyan), head-restrained animals (HR, gray), and chemically immobilized rats (CI, dark blue). d Functional connectivity matrix indicating mean regression coefficients (β) relating sensory and nonsensory brain areas (black and red labels, respectively). Seed regions are labeled on the vertical axis; shading = left hemisphere. Green boxes denote regions significantly nonzero across animals with FDR-corrected two-sided t test p ≤ 0.05 (n = 11). The white dashed box highlights connectivity between left and right somatosensory regions. e Map of average of functional connectivity to a seed region in S1BF (arrowhead), in chemically immobilized animals. Regression coefficients indicated for voxels with two-sided t test p ≤ 0.01 over n = 11 animals. Bregma coordinates in mm are indicated in yellow. f Regression maps indicating rsFC to S1BF seed regions (arrowheads) in anesthetized (top) and head-restrained (bottom) animals. Regression coefficients indicated for voxels with two-sided t test p ≤ 0.01 over n = 11 (top) or 6 (bottom) animals. g Mean homotopic S1BF regression coefficients for anesthetized (cyan) vs. chemically immobilized (dark blue) animals, both n = 11 animals; difference significant with paired t test 0.010. h Power spectra of resting-state fMRI signal in S1BF under anesthesia (cyan) or chemical immobilization (dark blue). Shading denotes SEM over 11 animals. i Mean spectral densities in the 0.01–0.1 Hz band corresponding to the dashed box in panel (h) (difference not significant with paired t test p = 0.18).