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Paracetamol - Effect of early exposure on neurotransmission, spatial memory and motor performance in rats
Kamilla Blecharz-Klin1, Agnieszka Piechal1, Katarzyna Jawna-Zboińska1
1Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland.
Insights
Early exposure to paracetamol (acetaminophen) in rats alters neurotransmission and behavior. Lower doses significantly impacted spatial memory and exploratory activity, suggesting potential developmental neurotoxicity.
Area of Science:
- Neuroscience
- Developmental Toxicology
- Pharmacology
Background:
- Prenatal and early life exposure to common medications like paracetamol (acetaminophen) raises concerns about potential neurodevelopmental effects.
- Understanding the impact of such exposures on neurotransmitter systems and subsequent behavior is crucial for public health.
- Rodent models offer a valuable platform for investigating these complex interactions.
Purpose of the Study:
- To investigate the effects of prenatal and early life paracetamol exposure on neurotransmission in male rat pups.
- To assess the behavioral manifestations, including spatial learning, memory, and exploratory activity, following early paracetamol exposure.
- To determine the impact on monoamine, metabolite, and amino acid levels in key brain regions.
Main Methods:
- Male rat pups were exposed to paracetamol during prenatal and early life.
- Behavioral assessments included the Staircase Test, Hole Board Test, and Water Maze.
- High-Performance Liquid Chromatography (HPLC) was used to measure neurotransmitter and amino acid concentrations in the prefrontal cortex, hippocampus, and striatum.
Main Results:
- Paracetamol exposure, particularly at lower doses, significantly affected spatial memory and exploratory behavior.
- Rats treated with paracetamol (5mg/kg) showed reduced motor activity and head-dipping, and altered performance in the Water Maze.
- Significant changes in serotonergic and dopaminergic neurotransmission were observed in the prefrontal cortex and striatum, alongside altered amino acid levels in the hippocampus and cortex.
Conclusions:
- Early life paracetamol exposure induces significant alterations in brain neurotransmission and amino acid profiles.
- These neurochemical changes are reflected in specific behavioral deficits, particularly in spatial learning and exploratory activity.
- The findings highlight the potential neurodevelopmental risks associated with early paracetamol exposure.
Abstract:
In the present study we examined the effect of prenatal and early life paracetamol exposure on neurotransmission and its behavioural manifestation in rat male pups. In order to assess the ability of spatial learning and memory consolidation and the level of physical and exploratory activity we conducted a series of behavioural tests: Staircase Test, Hole Board Test and Water Maze. The concentrations of monoamines, metabolites and amino acids were determined using High Performance Liquid Chromatography in the prefrontal cortex, hippocampus and striatum. The effect on spatial memory and exploratory behaviour was most pronounced in animals treated with the lower dose of paracetamol. In this group we have observed a much lower motor activity and decreased head-dipping behaviour. Simultaneously, the number of crossings in the Water Maze under the previous platform position during the probe trial was significantly higher in rats treated with paracetamol at the dose of 5mg/kg. There was also a preference for a new location of a platform to the original position of the platform in the reversal probe trial of this group. These results indicate that early paracetamol exposure produces major changes in serotonergic and dopaminergic neurotransmission in the prefrontal cortex and striatum. At the same time, administration of the drug in early life results in the spectacular change in the amino acid level, in particular in the hippocampus and cortex. This has been reflected in the behaviour of animals in the Water Maze and Hole Board Test (without any noticeable impact on the Staircase Test).
