Long-term functional neurotoxicity of paraoxon and chlorpyrifos: behavioural and pharmacological evidence

Neurotoxicol Teratol. 2004 Mar-Apr;26(2):305-17. doi: 10.1016/j.ntt.2003.10.008.

Abstract

Organophosphate (OP) compounds are chemicals widely used in agriculture, industry and households and even as chemical weapons. The major mechanism of acute toxic action is the inhibition of acetylcholinesterase (AChE), which is responsible for the degradation of the neurotransmitter acetylcholine. A chronic OP-induced neuropsychiatric disorder (COPIND), which could result from both long-term exposure to subclinical doses of OP and after acute intoxication, has been proposed. These reports claim to develop animal models that could parallel behavioural and cognitive effects and that could later help to elucidate the mechanisms involved in this long-term affectation of the central nervous system. The present study uses a series of behavioural tests to discern the short- and long-term effects of acute intoxications with paraoxon (Px) or chlorpyrifos (CPF). Our results suggest that months after acute exposure to these OPs functional central nervous system alterations can be detected using a repeated acquisition spatial task in the water maze, for CPF, and in amphetamine-induced place preference paradigm, for both Px and CPF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphetamine / pharmacology
  • Animals
  • Arecoline / pharmacology
  • Behavior, Animal / drug effects*
  • Central Nervous System Stimulants / pharmacology
  • Chlorpyrifos / toxicity*
  • Cholinergic Agonists / pharmacology
  • Cholinesterase Inhibitors / metabolism
  • Clozapine / pharmacology
  • Conditioning, Operant / drug effects
  • Dopamine Antagonists / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Haloperidol / pharmacology
  • Insecticides / toxicity*
  • Male
  • Maze Learning / drug effects
  • Muscarinic Antagonists / pharmacology
  • Neurotoxicity Syndromes / etiology*
  • Neurotoxicity Syndromes / physiopathology
  • Paraoxon / toxicity*
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Reaction Time / drug effects
  • Scopolamine / pharmacology
  • Serotonin Antagonists / pharmacology
  • Spatial Behavior / drug effects
  • Time*

Substances

  • Central Nervous System Stimulants
  • Cholinergic Agonists
  • Cholinesterase Inhibitors
  • Dopamine Antagonists
  • Insecticides
  • Muscarinic Antagonists
  • Serotonin Antagonists
  • Arecoline
  • Amphetamine
  • Scopolamine
  • Clozapine
  • Haloperidol
  • Chlorpyrifos
  • Paraoxon