Monomethyl-and trimethyltin compounds induce learning deficiencies in young rats

Male rat pups were exposed to monomethyltin trichloride (MMTC) and trimethyltin chloride (TMTC) via their dams' drinking water throughout gestation and post partum until 21 days of age. At 11 days of age, the pups were tested for acquisition and extinction learning ability in an appetitive learning paradigm, and at 21 days for learning ability in a one trial swim escape learning test. At 11 days, pups from dams exposed to 120 mg/l Sn as MMTC and to 1.0 mg/l Sn as TMTC displayed statistically significant increases in acquisition time, while all dose groups (12, 40, 120 mg/l MMTC and 0.15, 0.5, 1.0 mg/l TMTC) displayed significant decreases in extinction learning ability as compared to controls. At 21 days of age, animals exposed to 12 mg/l and 120 mg/l MMTC displayed higher escape times than controls, as did animals exposed to 0.5 mg/l TMTC.