Methylmercury causes neuronal cell death via M1-microglial activation in organotypic slices prepared from mouse cerebral cortex

Abstract

Methylmercury is an environmental pollutant that causes central nervous system injury. We reported that the expression of the inflammatory cytokines TNF-α and IL-1β was specifically induced in the brains of methylmercury-treated mice. In addition, we recently found that cytotoxic microglia (M1-microglia) may be involved in the induction of inflammatory cytokine expression by methylmercury in mouse cerebral slice cultures. In the current study, we investigated the involvement of M1-microglia in the neuronal cell death caused by methylmercury using mouse cerebral slice cultures. The results revealed that methylmercury activated steady state microglia (M0-microglia) to M1-microglia, but this activation was suppressed by pretreatment with minocycline, a microglial activation inhibitor. In addition, under the same conditions, minocycline suppressed neuronal cell death by methylmercury. These results suggest that methylmercury may induce neuronal cell death via activation to M1-microglia.