Subacute Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine Exposure Induces Neurobehavioral Deficits and Hippocampal Demyelination in Mice.

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) is a nitramine explosive widely used in military and industrial fields. While emerging evidence suggests the neurotoxicity of HMX, the mechanisms underlying central nervous system (CNS) damage remain largely unknown. In the present study, we established a mouse model of 28-day subacute HMX exposure to explore HMX-induced neurotoxicity and underlying mechanisms in vivo. Behavioral assessments revealed that HMX increased spontaneous locomotor activity and central exploration in the open field test, and reduced immobility time in the forced swimming test, indicating abnormal emotional regulation. The Morris water maze further demonstrated impaired hippocampus-dependent spatial learning and memory in HMX-treated mice, as evidenced by prolonged platform latency. Histopathological analysis showed hippocampal demyelination in HMX-treated mice, accompanied by downregulation of myelin structural proteins (MBP, PLP1) and oligodendrocyte lineage proteins (OLIG2, CNPase). Additionally, proteomic analysis identified 173 differentially expressed proteins in the HMX-exposed hippocampus, which were enriched in myelination, synaptic transmission and neuroactive ligand-receptor interaction pathways. Collectively, our findings demonstrate that subacute HMX exposure induces behavioral deficits and demyelination in mice hippocampus, providing a novel mechanistic insight into HMX neurotoxicity and a theoretical basis for occupational health protection against HMX exposure.