Minocycline improves cognition and molecular measures of inflammation and neurodegeneration following repetitive mTBI
To investigate minocycline treatment of mTBI neuroinflammation, we utilised a validated mouse model involving repetitive impact-induced rotational acceleration. Adult male C57BL/6J mice were randomly assigned into one of four impact groups (vehicle control; minocycline without impact; minocycline with impact, and vehicle with impact). 15 mTBIs were delivered, and outcomes were assessed 48 hours and 3 months following the final mTBI to assess the acute and chronic inflammatory responses. Hippocampal spatial learning and memory testing revealed no differences in the minocycline impact group compared to unimpacted controls in the chronic phase of recovery, indicating chronic neuroprotection. mRNA analyses were performed on brain tissue samples of the cortex and hippocampus using quantitative RT-PCR. Minocycline treatment of mTBI lead to improvement in microglial activation, inflammation, excitotoxicity, and neuron integrity in the chronic stage of recovery. These data suggest that minocycline treatment alleviated some mTBI pathophysiology and clinical features at chronic time-points.