Behavioral and neurochemical changes associated with chronic exposure to low-level concentration of pesticide mixtures.
In order to assess behavioral and neurochemical changes resulting from pesticide exposure, food-restricted male weanling rats were exposed for 90 d to low doses (1 ppb-10,000 ppb range) of individual pesticides (aldicarb, metribuzin, or methomyl) or mixtures of them. During exposure, rats were trained to run a T-maze and tested for spatial discrimination reversal learning. At sacrifice, three brain regions (cortex, hippocampus, and neostriatum) were assayed for the neurotransmitters dopamine, acetylcholine, and serotonin. Animals treated with a mixture of two insecticides and one herbicide were found to have slower speeds in maze-running (motor control) and also had altered levels of choline in their neostriatums. Rats treated with one herbicide compound (metribuzin) took longer to learn on two reversals; this group also had a significantly lower acetylcholine/choline ratio in their hippocampus.
Boyd
C A
CA
Environmental Toxicology Center, University of Wisconsin, Madison 53706.
Weiler
M H
MH
Porter
W P
WP
D000448:Aldicarb / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D003657:Decision Making / Q000187:drug effects; D004338:Drug Combinations; D004357:Drug Synergism; D006540:Herbicides / Q000494:pharmacology; D006624:Hippocampus / Q000378:metabolism; D007107:Immune System / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D008724:Methomyl / Q000494:pharmacology; D010575:Pesticides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014227:Triazines / Q000494:pharmacology
D004338:Drug Combinations; D006540:Herbicides; D010575:Pesticides; D014227:Triazines; D008724:Methomyl; D000448:Aldicarb; D002794:Choline; C009235:metribuzin