Fig. 7.

Schematic of signaling pathways involved in methamphetamine-induced astrocyte activation via an autocrine mechanism of HMGB1 expression. Exposure of astrocytes to methamphetamine leads to activation and migration of astrocytes via up-regulation of HMGB1. Inhibition of σ-1R, Src, or ERK MAPKs results in the subsequent inactivation of the downstream NF-κB p65 transcription factor. NF-κB p65 enhances HMGB1 expression and subsequently induces astrocyte activation and migration, thereby amplifying the methamphetamine response