Changes in Cerebral Glucose Metabolism at Rest Following Hemicontusive Cervical 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 adult, female mice to assess functional brain reorganization in a subacute stage (1 week after SCI). Right moderate contusive injury at the cervical 5 level 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. 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 ascending and descending neural pathways in both hemispheres. In addition, functional metabolic connectivity between the ventral posterolateral thalamic nucleus and primary somatosensory cortex was bilaterally decreased. The current preliminary findings underscore the broadness of brain reorganization in the subacute stage following a unilateral contusive-type SCI. Functional whole-brain metabolic mapping provides a roadmap for future targeted studies examining neuroplastic markers to evaluate new therapeutic strategies.