Changes in cerebral glucose metabolism at rest following hemicontusive spinal cord injury in mice: A whole-brain autoradiographic study

Spinal cord injury (SCI) disrupts brain-spinal cord communications and results in profound brain reorganization. Here, we apply high-resolution, voxel-based, whole-brain metabolic mapping using the [14C]-2-deoxyglucose autoradiographic method in mice to assess functional brain reorganization in a subacute stage (1 week after SCI). Right moderate contusive injury at the cervical 5 level (C5) was confirmed by glial fibrillary acidic protein (GFAP) immunohistochemical staining. SCI compared to sham-lesioned animals showed significant motor deficits (grip strength, rotarod) alongside decreases in glucose uptake in sensorimotor regions of the cortex, basal ganglia, and thalamus, which receive monosynaptic afferents (the ventral posterolateral thalamic nucleus, VPL) or multi-synaptic afferents from the spinal cord (the primary somatosensory and motor cortices, caudate putamen). In contrast, regions in the limbic system (the amygdala, accumbens nucleus, lateral septum, and hippocampus) and in the cerebellum demonstrated increases in glucose uptake in SCI animals. Most of these effects were noted bilaterally, suggesting functional reorganization involving higher order neural circuits bilaterally. The current findings underscore the broadness of brain reorganization in the subacute stage following incomplete SCI. Functional whole-brain metabolic mapping provides a roadmap for future targeted studies examining neuroplastic mechanisms in search of new therapeutic strategies.