To assess the alterations in resting-state functions and neural structures in the brain of a heatstroke rat model and explore the underlying relationship.

In total, 17 male Sprague Dawley rats were randomly divided into a control group (CTRL, n = 7) and a heatstroke group (HS, n = 10). All rats underwent 7.0 T magnetic resonance imaging (MRI). T2-weighted imaging, resting-state functional MRI (rs-fMRI), and diffusion tensor imaging (DTI) were obtained. On day 25, the surviving HS group rats (the follow-up group, FU, n = 7) were scanned again.

Heatstroke resulted in functional alterations and structural damage in the cerebellar molecular layer (CML), right perirhinal area (PA), pretectal region (PR), right dentate gyrus, and external cortex of the inferior colliculus (ECIC). Further functional changes occur in the right temporal associative cortex (TAC), left retrosplenial cortex (RC), and CML during convalescence. The fractional anisotropy values were significantly positively correlated with the amplitude of low-frequency fluctuation (ALFF) (HS–CML: r = 0.746, p = 0.034; right PR: r = 0.648, p = 0.049; FU–right PA: r = 0.817, p = 0.025)/regional homogeneity (ReHo) ratio (HS–CML: r = 0.833, p = 0.008; ECIC: r = 0.678, p = 0.045) and negatively correlated with the ALFF (FU–left RC: r = −0.818, p = 0.024; right TAC: r = −0.813, p = 0.049).

DTI and rs-fMRI allow meticulous monitoring of the progression of neurological and functional alterations in the brain after heatstroke.

Heatstroke

Resting-state functional magnetic resonance imaging

Diffusion tensor imaging

Rat

Magnetic resonance imaging

resting-state functional magnetic resonance imaging

diffusion tensor imaging

amplitude of low-frequency fluctuation

receiver operating characteristic curves

cerebellar molecular layer

external cortex of the inferior colliculus

temporal associative cortex

blood oxygen level dependence

Magnetic resonance imaging

smoothened and mean ReHo

© 2022 Elsevier Inc. All rights reserved.