Artigo Acesso aberto Produção Nacional Revisado por pares

Methamidophos Exposure During the Early Postnatal Period of Mice: Immediate and Late-Emergent Effects on the Cholinergic and Serotonergic Systems and Behavior

2013; Oxford University Press; Volume: 134; Issue: 1 Linguagem: Inglês

10.1093/toxsci/kft095

ISSN

1096-6080

Autores

Carla S. Lima, Ana Carolina Dutra-Tavares, Fernanda Costa Nunes, André L. Nunes‐Freitas, Anderson Ribeiro‐Carvalho, Cláudio C. Filgueiras, Alex C. Manhães, Armando Meyer, Yael Abreu‐Villaça,

Tópico(s)

Pesticide and Herbicide Environmental Studies

Resumo

Organophosphates (OPs) are among the most used pesticides. Although some OPs have had their use progressively more restricted, other OPs are being used without sufficient investigation of their effects. Here, we investigated the immediate neurochemical and delayed neurochemical and behavioral actions of the OP methamidophos to verify whether there are concerns regarding exposure during early postnatal development. From the third to the nineth postnatal day (PN), Swiss mice were sc injected with methamidophos (1mg/kg). At PN10, we assessed cholinergic and serotonergic biomarkers in the cerebral cortex and brainstem. From PN60 to PN63, mice were submitted to a battery of behavioral tests and subsequently to biochemical analyses. At PN10, the effects were restricted to females and to the cholinergic system: Methamidophos promoted increased choline transporter binding in the brainstem. At PN63, in the brainstem, there was a decrease in choline transporter, a female-only decrease in 5HT1A and a male-only increase in 5HT2 receptor binding. In the cortex, choline acetyltransferase activity was decreased and 5HT2 receptor binding was increased both in males and females. Methamidophos elicited behavioral alterations, suggestive of increased depressive-like behavior and impaired decision making. There were no significant alterations on anxiety-related measures and on memory/learning. Methamidophos elicited cholinergic and serotonergic alterations that depended on brain region, sex, and age of the animals. These outcomes, together with the behavioral effects, indicate that this OP is deleterious to the developing brain and that alterations are indeed identified long after the end of exposure.

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