You are here:
COMPARISON OF EEG CHANGES PRODUCED BY CARBARYL (CARBAMATE), PERMETHRIN (TYPE I PYRETHROID), AND DELTAMETHRIN (TYPE II PYRETHROID)
Citation:
LYKE, D. F. AND D. W. HERR. COMPARISON OF EEG CHANGES PRODUCED BY CARBARYL (CARBAMATE), PERMETHRIN (TYPE I PYRETHROID), AND DELTAMETHRIN (TYPE II PYRETHROID). Presented at Society of Toxicology 49th Annual meeting, Salt Lake City, UT, March 07 - 11, 2010.
Impact/Purpose:
The results indicate that the non-stimulus driven EEG was differentially altered by pesticides with different modes of action.
Description:
We have reported that treatment with carbaryl may alter Theta activity in the EEG (Lyke et al., Toxicologist, 108(S-1):441, 2009). In this study, we examined the ability to detect changes in EEG activity produced by pesticides with different modes of action. Long Evans rats were implanted with epidural screw electrodes. After recovery, non-restrained animals were gavaged with corn oil and tested for 2 days for acclimation. On day 3, the rats were dosed (po) with vehicle (corn oil), a carbamate (carbaryl, 50 mglkg), a Type I (Permethrin, 42 mglkg), or a Type II pyrethroid (Deltamethrin, 2.5 mglkg). The carbaryltreated animals and their controls were tested 30 min later. The pyrethroid-treated animals and their controls were tested 2 h later. These times were associated with maximal inhibition of brain cholinesterase (carbaryl), or peak time of inhibition of motor activity for the pyrethroids (about an ED30 dosage). EEG was recorded as 30 segments of 2s, transformed using a FFT, and the spectra averaged. Because of the different time of maximal effect for the different classes of chemicals, the data were transformed as a percent of their respective control mean. Treatment with carbaryl reduced the peak frequency for the slower components of the EEG (Delta and Theta, 64-79% of control) compared to the pyrethroids (92-107% of control). Permethrin increased the amplitude and/or area of multiple higher frequency regions of the EEG (Alpha, Beta, Gamma, 109-125% of control) compared to carbaryl (70-102% of control) and/or deltamethrin (82-98% of control). The results indicate that the non-stimulus driven EEG was differentially altered by pesticides with different modes of action. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.