Frederic J. Seidler

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Chlorpyrifos, one of the most widely used pesticides, exhibits greater toxicity during development than in adulthood. We administered chlorpyrifos to neonatal rats in apparently subtoxic doses that caused no mortality and little or no weight deficits and examined developing brain regions (cerebellum, forebrain, brainstem) for signs of interference with cell(More)
The widely used organophosphate pesticide chlorpyrifos is a suspected neuroteratogen. In the current study, we compared the effects of chlorpyrifos and its major metabolites in two in vitro models, neuronotypic PC12 cells and gliotypic C6 cells. Chlorpyrifos inhibited DNA synthesis in both cell lines but had a greater effect on gliotypic cells. Chlorpyrifos(More)
Developmental neurotoxicity caused by chlorpyrifos exposure is generally thought to target cholinesterase but chlorpyrifos may also act on cellular intermediates, such as adenylyl cyclase, that serve global functions in the coordination of cell development. In the current study, neonatal rats were exposed to apparently subtoxic doses of chlorpyrifos (no(More)
The widespread use of chlorpyrifos has raised concern about the potential consequences of fetal and childhood exposure. Previous studies have shown that apparently subtoxic doses of chlorpyrifos are nevertheless capable of affecting brain development by inhibiting mitosis, eliciting apoptosis, and altering neuronal activity and reactivity. To determine(More)
Chlorpyrifos is a widely used organophosphate insecticide that is a suspected developmental neurotoxin. Although chlorpyrifos exerts some effects through cholinesterase inhibition, recent studies suggest additional, direct actions on developing cells. We assessed the effects of chlorpyrifos on nuclear transcription factors involved in cell replication and(More)
After routine home application of chlorpyrifos (CPF), infant and child exposures can exceed acceptable levels. We treated neonatal rats daily on postnatal days (PN) 1-4 (1 mg/kg) or days 11-14 (5 mg/kg), treatments that evoked no overt signs of toxicity. Effects on the development of cholinergic neuronal function were assessed using choline(More)
The commonly-used organophosphate insecticide, chlorpyrifos (CPF), impairs brain cell development, axonogenesis and synaptogenesis. In the current study, we administered CPF to neonatal rats on postnatal (PN) days 1-4 (1 mg/kg) or PN11-14 (5 mg/kg), treatments that were devoid of overt toxicity. We then examined two cholinergic synaptic markers, choline(More)
Developmental exposure to chlorpyrifos (CPF) causes persistent changes in serotonergic (5HT) systems. We administered 1 mg/kg/day CPF to rats on postnatal days 1-4, a regimen below the threshold for systemic toxicity. When tested in adulthood, CPF-exposed animals showed abnormalities in behavioral tests that involve 5HT mechanisms. In the elevated plus(More)
Nearly all smokers begin tobacco use in adolescence, and approximately 25% of US teenagers are daily smokers. Prenatal nicotine exposure is known to produce brain damage, to alter synaptic function and to cause behavioral anomalies, but little or no work has been done to determine if the adolescent brain is also vulnerable. We examined the effect of(More)
During brain development, serotonin (5HT) provides essential neurotrophic signals, and in earlier work, we found that developmental exposure to chlorpyrifos (CPF) elicits short-term changes in 5HT systems. In the present study, we evaluated the effects in adulthood after CPF exposures from the neural tube stage [gestational days (GD) 9-12] and the late(More)