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Updated: Aug 14, 2026
Isolation and Expansion of Adult Canine Hippocampal Neural Precursors
Published on: November 29, 2016
Paraoxon-induced ultrastructural growth changes of rat cultured hippocampal cells in neurobasal/B27
M Yousefpour1, F Bahrami, B Shahsavan Behboodi
1Research Center for Chemical Injuries, Baqiyatallah University of Medical Science, Tehran, Iran. yousefpour_mi@yahoo.com
Abstract:
Organophosphates (OPs) neurotoxicity is attributed both to their well-known cholinergic and recently attended non-cholinergic effects. Since parathion has been observed to be responsible for more cases of poisoning than any other OP insecticides, it is vitally important to investigate other mechanisms, besides cholinesterase inhibition, which can potentially contribute to the neurotoxicity of parathion (or its metabolite, paraoxon). In present study, hippocampal cells obtained from Wistar rat neonates were cultured in neurobasal medium supplemented with B27 serum where different doses of paraoxon were also introduced. The neuronal growth in the control group and those exposed to paraoxon was compared. Phase contrast microscopy, cell staining (Neutral Red) and computer assessment morphometric study (Motic) were used to study cell morphology, viability and type of cell death. Statistical analysis was carried out using one-way ANOVA. There was no clear morphologic differences between neurons in the control group and those exposed to 10 microM paraoxon; however, deformity of the soma was clear in pellets containing higher concentration of paraoxon. Ultrastructure of cells was markedly altered at 50 microM dose of paraoxon as evidenced by gradual discontinuation of cytoplasm, appearing of numerous vacuoles and intracytoplasmic myelin figure. The processes (neurites) did not grow in media containing 100 microM paraoxon or more. Viability decreased with increasing paraoxon especially above 100 microM. In conclusion, the present data reveal that paraoxon, in 30 microM or higher concentrations, induces a decrease in cell growth, followed by cell swelling and neuronal death (possibly necrosis).
Insights
Organophosphates, like parathion, cause neurotoxicity through non-cholinergic effects. High paraoxon concentrations damage hippocampal cells, reduce growth, and cause neuronal death, indicating a significant risk beyond cholinesterase inhibition.
Area of Science:
- Neuroscience
- Toxicology
- Cell Biology
Background:
- Organophosphates (OPs) are known for cholinergic neurotoxicity.
- Parathion, a common OP insecticide, has significant poisoning cases.
- Non-cholinergic mechanisms of OP neurotoxicity require further investigation.
Purpose of the Study:
- To investigate the non-cholinergic neurotoxic effects of paraoxon, a parathion metabolite, on cultured hippocampal cells.
- To assess the impact of varying paraoxon concentrations on neuronal morphology, viability, and cell death.
Main Methods:
- Primary hippocampal cell cultures from Wistar rat neonates.
- Exposure to different concentrations of paraoxon.
- Morphological analysis using phase contrast microscopy and Motic.
- Cell viability assessment using Neutral Red staining.
- Statistical analysis using one-way ANOVA.
Main Results:
- Paraoxon concentrations of 30 microM and higher reduced cell growth.
- Significant alterations in cell ultrastructure, including cytoplasmic changes and vacuoles, observed at 50 microM.
- Neurite outgrowth was inhibited at 100 microM paraoxon.
- Cell viability decreased with increasing paraoxon concentrations, particularly above 100 microM.
- Neuronal death, possibly necrosis, was induced by paraoxon.
Conclusions:
- Paraoxon exhibits significant non-cholinergic neurotoxicity.
- Concentration-dependent effects of paraoxon on neuronal cells include growth inhibition, morphological damage, and cell death.
- These findings highlight the critical need to understand paraoxon's broader toxicological profile beyond cholinesterase inhibition.
