TNF and Mental deterioration: PQ increases interferon-gamma(IFN-γ) blood levels,7 and INF-γknockout in mice reverts thePQ-induced expression of c-Jun-N-terminal-kinase (JNK), activatorof transcription-1 (STAT1), and proinflammatory cytokines as tumor-necrosis-factor-α(TNF-α) and the neuronal loss induced in substantia nigra.8 Long-term treatment with INF-γ in miceinduces hippocampal neurodegeneration and cognitive decline throughJanus kinases (JAK)/STAT1 pathway,9 whichis induced by TNF-α upregulation.10 Thus, PQ could mediate hippocampal neurodegeneration through IFN-γupregulation.