Bacterial lipopolysaccharide model of neuroinflammation-associated neurodegeneration in Wistar rats: A comparison between different durations of lipopolysaccharide induction.

BACKGROUND AND AIM

Bacterial lipopolysaccharide (LPS)-induced neuroinflammation can be the most dependable animal model for studying neurodegeneration mechanisms driven by systemic inflammation-induced neuroinflammation. Hence, this study aimed to standardize the LPS model of neuroinflammation by comparing the effect of relatively low-dose LPS administered for different durations on the induction of neurodegeneration in Wistar rats.

MATERIALS AND METHODS

Six groups of six adult Wistar rats per group were used in the study. Group 1 was the control group, and the other five were administered single weekly dose of LPS (170 μg/kg) for increasing durations, ranging from 4 weeks to 8 weeks. The study endpoints included behavioral parameters, neuronal assay results, and the expression of microglia and astrocytes in the frontal cortex, dentate gyrus, and hippocampus.

RESULTS

We observed a significant reduction in the number of neurons and an increase in glial cells at 5 weeks of exposure, along with a decline in memory. Thereafter, these changes were gradual until 7 weeks of exposure. However, at 8 weeks of exposure, there was no further statistically significant worsening compared with the group exposed for 7 weeks.

CONCLUSION

To effectively induce neuroinflammation and cause neuronal damage, a minimum of five weekly LPS administrations at a dose of 170 μg/kg is required. Moreover, our results recommend a maximum of 7 weeks of LPS exposure to create a chronic inflammatory model of neuroinflammation.