Changes of brain evoked potentials caused by dimethoate treatment in three generations of rats.

Wistar rats were continuously treated with 7.0, 10.5, 14.0, and 28.0 mg/kg (1/100, 1/70, 1/50 and 1/25 LD50) of dimethoate per os including the pregnancy and lactation periods for three subsequent generations. The somatosensory, visual and auditory evoked brain potentials of male rats of each generation were registered at the age of 12-13 weeks with silver electrodes placed on the primary somatosensory, visual and auditory cortex. The measured parameters were the latency and duration of the evoked potentials. There were differences in the changes among the various evoked potentials in all of the generations. The strongest effect caused by dimethoate was seen in the case of the somatosensory evoked potentials compared to the control. The changes of the visual and auditory evoked potentials were milder. Comparing the changes of the evoked potentials of the three generations it was found that there were no significant changes between the data of the three populations.