Neurotoxic effects of mercury: in vitro and in vivo studies

Pollution remains a major global public health challenge, with mercury recognized as a highly hazardous environmental toxicant because of its persistence, bioaccumulation, and pronounced neurotoxicity. Mercury occurs in elemental, inorganic, and organic forms, particularly methylmercury (MeHg), which readily accumulates in biological systems and adversely affects the central nervous system. This narrative review summarizes current evidence on mercury-induced neurotoxicity, focusing on oxidative stress, neuroinflammation, mitochondrial dysfunction, altered energy metabolism, excitotoxicity, neurodevelopmental toxicity, epigenetic alterations, and disruption of neuronal signaling. The effects of mercury exposure on neural cell populations, including neurons, astrocytes, and oligodendrocytes, are also discussed, with particular emphasis on vulnerable populations such as pregnant women, fetuses, and children. Despite substantial progress, important gaps remain regarding long-term neurological outcomes, molecular mechanisms, dose-response relationships, sex-dependent susceptibility, and effective therapeutic interventions.A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar during January-February 2026 for studies published up to February 2026. The search combined terms related to mercury exposure and neurotoxicity, including "mercury," "methylmercury," "mercury exposure," "neurotoxicity," "oxidative stress," "neuroinflammation," "mitochondrial dysfunction," "neurodevelopment," and "epigenetic alterations,". Original research and relevant English-language reviews were included, while editorials, conference abstracts, duplicates, and studies unrelated to mercury-induced neurological effects were excluded. Titles and abstracts were screened, followed by full-text assessment of potentially relevant studies. As this was a narrative review, no formal risk-of-bias or quality-of-evidence assessment was performed.