THIM is metabolized in the body to ethyl mercury (EtHg) and subsequently to inorganic mercury forms, which accumulate in tissues of vital organs, including the brain (22). Information about neurochemical and neurotoxic effects of THIM is still limited, but the existing data indicate that in pharmacodynamics and toxicity THIM/EtHg does not differ significantly from methyl mercury (MeHg), which has been studied more extensively, although these compounds differ somewhat in pharmacokinetics (8).