EEG changes caused by dimethoate treatment in three generations of rats

Wistar rats were continuously treated with 7.0, 10.5, 14.0, 28.0 mg/kg (1/100, 1/75, 1/50 and 1/25 LD50) of dimethoate per os including the pregnancy of dams and the lactation period of pups as well as in adulthood for three subsequent generations. The EEG of male rats of each generation was recorded at the age of 12-13 weeks. The mean frequency, mean amplitude, EEG index and the power spectrum were analysed. The data showed that the overall EEG activity of the treated rats was greater than of the controls. The mean frequency was higher, the mean amplitude and the EEG index were lower, the activity of the lower frequency wave bands decreased, that of the higher frequency wave bands increased. The changes of the mentioned EEG parameters were most pronounced in the third generation.