Ricardo O. Duffard

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Neonate rats were exposed to 100 mg/kg from the PND 7 to PND 25 or at 70 mg/kg from PND 12 to PND 25. Treated and control pups were subjected to several behavioral tests (righting reflex, negative geotaxy, forelimbs support and open field) during the period of treatment. At PND 25 the regional effects of 2,4-D on gangliosides composition and myelin(More)
Our results show that 2,4-dichlorophenoxyacetic acid (2,4-D) exposure through mother's milk during the period of rapid myelination (from the 15th to the 25th postnatal days) results in a myelin deficit in the pup's brain and demonstrates the vulnerability of the developing central nervous system (CNS) to 2,4-D. After 100 mg/kg 2,4-D administration to dams,(More)
Although the mechanism of 2,4-D neurotoxicity remains unknown the serotonergic system appears to mediate some of the effects of 2,4-D in rats as reported in our previous studies. In the present study we examine the concept that a challenge to a system may overcome compensatory mechanisms and thereby reveal otherwise hidden neurotoxicant-induced damage. We(More)
2,4-Dichlorophenoxyacetic acid (2,4-D), a worldwide-used herbicide, has been shown to produce a wide range of adverse effects in the health—from embryotoxicity and teratogenicity to neurotoxicity—of animals and humans. In this study, neuronal morphology and biochemical events in rat cerebellar granule cell (CGC) cultures have been analyzed to define some of(More)
The purpose of this study was to determine whether the behavioral development pattern was altered by a pre- and postnatal exposure to 2,4-Dichlorophenoxyacetic acid (2,4-D). Pregnant rats were daily orally exposed to 70 mg/kg/day of 2,4-D from gestation day (GD) 16 to postnatal day (PND) 23. After weaning, the pups were assigned to one of the two subgroups:(More)
2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most widely used herbicides due to its relatively moderate toxicity and to its biodegrad-ability in the soil. In toxic concentrations, 2,4- D displays strong neurotoxicity, partly due to generation of free radicals. Since melatonin has remarkable antioxidant properties, the objective of this study was to(More)
2,4-Dichlorophenoxyacetic acid (2,4-D) and its derivatives are herbicides widely used to control the growth of broadleaf and woody plant. Human and animal exposure to 2,4-D through agriculture use, food products, or use in lawn and garden care has been well documented, but little information is available on the transfer from serum to milk in exposed dams.(More)
Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a(More)
2,4-Dichlorophenoxyacetic acid (2,4-D) is a potent neurotoxic herbicide widely used in agriculture. The basic mechanisms by which 2,4-D produces cell damage have not yet been determined. In this study we have examined the effects of 2,4-D in primary cultures of cerebellar granule cells in order to obtain insights into the possible mechanisms underlying the(More)