A novel mouse model of combined blast and carbon monoxide-induced brain injury recapitulating coal mine gas explosions.

Coal mine gas explosions expose victims to concurrent blast-wave injury and carbon monoxide poisoning, producing complex brain damage that is not well captured by existing animal models. Here, we established a mouse model combining methane-air blast exposure in a closed shock tube with acute systemic carbon monoxide administration. Male C57BL/6 mice were assigned to normal control, blast-wave injury (BW), carbon monoxide poisoning (CO), or combined BW + CO injury groups. Behavioral testing, histology, injury biomarker analysis, inflammatory assays, and RNA sequencing were used to compare single and combined insults. Compared with either BW or CO alone, BW + CO injury produced broader and more persistent deficits in anxiety-like behavior, spatial learning and memory, working memory, and motor coordination. Combined injury also aggravated neurovascular pathology, neuronal loss, glial activation, neuronal injury marker expression, and inflammatory cytokine responses. RNA sequencing at 24 h revealed region-selective transcriptomic profiles. Hippocampal responses were enriched for synaptic/neuropeptide signaling and extracellular-matrix changes, whereas cortical responses showed metabolic reprogramming, synaptic pathway alterations, and immune-pathway modulation. Together, these findings indicate that combined blast and CO exposure induces a distinct pathological state consistent with a biologically interactive or non-additive combined effect, although formal interaction modeling was not performed. This model provides a controlled platform for studying acute and subacute mechanisms of complex CNS injury relevant to coal mine gas explosions and for testing targeted therapeutic strategies.