Repeated exposures to low-level chlorpyrifos results in impairments in sustained attention and increased impulsivity in rats

M. L. Middlemore-Risher, J. J. Buccafusco, Alvin V Terry

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Organophosphates such as chlorpyrifos (CPF) are among the most commonly used pesticides in the world. Therefore, it is not surprising that measurable levels of organophosphates (including CPF) are found in over 50% of fresh fruits, vegetables and grains that we consume and that approximately 80% of adults in the US have detectable levels of CPF metabolites in their urine. It is well known that acute exposure to organophosphates can cause cognitive deficits; however, the effects of daily or intermittent contact with low levels of organophosphates (often reflective of environmental exposures) are not well understood. The objective of this study was to determine if repeated low-level exposures to CPF impaired the performance of the 5-Choice Serial Reaction Time Task (5C-SRTT), an animal model of sustained attention. Adult rats were trained to stably perform the 5C-SRTT, then treated with vehicle or CPF 18.0. mg/kg daily for 14 consecutive days or every other day for 30. days. Behavioral testing occurred daily during the CPF-exposure period and throughout a 30. day washout period to assess recovery. All CPF-treated animals exhibited deficits in percent correct, an increase in omissions and premature responses without signs of impaired motivation or overt toxicity. Deficits in 5C-SRTT accuracy were apparent well into the 30. day washout period despite significant recovery of cholinesterase activity. These results indicate that repeated exposures to relatively low levels of chlorpyrifos lead to protracted impairments of sustained attention and an increase in impulsive behaviors in rats.

Original languageEnglish (US)
Pages (from-to)415-424
Number of pages10
JournalNeurotoxicology and Teratology
Volume32
Issue number4
DOIs
StatePublished - Jul 1 2010

Fingerprint

Chlorpyrifos
Impulsive Behavior
Rats
Organophosphates
Reaction Time
Animals
Recovery
Cholinesterases
Environmental Exposure
Vegetables
Metabolites
Fruits
Pesticides
Toxicity
Motivation
Fruit
Animal Models
Urine
Testing

Keywords

  • Cholinesterase inhibitor
  • Chronic
  • Cognition
  • Memory
  • Organophosphate
  • Pesticide

ASJC Scopus subject areas

  • Toxicology
  • Developmental Neuroscience
  • Cellular and Molecular Neuroscience

Cite this

Repeated exposures to low-level chlorpyrifos results in impairments in sustained attention and increased impulsivity in rats. / Middlemore-Risher, M. L.; Buccafusco, J. J.; Terry, Alvin V.

In: Neurotoxicology and Teratology, Vol. 32, No. 4, 01.07.2010, p. 415-424.

Research output: Contribution to journalArticle

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