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 adult
hood for three subsequent generations. The EEG of male rats of each ge
neration was recorded at the age of 12-73 weeks. The mean frequency, m
ean amplitude, EEG index and the power spectrum were analysed. The dat
a showed that the overall EEG activity of the treated rats was greater
than of the controls. The mean frequency was higher, the mean amplitu
de and the EEG index were lower, the activity of the lower frequency w
ave bands decreased, that of the higher frequency wave bands increased
. The changes of the mentioned EEG parameters were most pronounced in
the third generation. (C) 1994 Intox Press, Inc.