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Updated: May 6, 2026
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Differential microglial and astrocytic response to bacterial and viral infection in the developing hippocampus of
Nisha Patro1, Kavita Singh, Ishan Patro
1School of Studies in Neuroscience, Jiwaji University, Gwalior 474 011, India.
Abstract:
Polyinosinic:polycytidylic acid (Poly I:C; 5 mg/kg body weight, ip) and lipopolysaccharide (LPS; 0.3 mg/kg body weight, ip) induced microglial and astrocytic activation in Sprague Dawley rats. Higher microglial and astrocytic activities were noticed in Poly I:C infused rats throughout the hippocampus till postnatal day 21 with a comparatively weaker response in LPS group. However, LPS induced inflammation persisted even after postnatal day 21, indicating thereby, that the Poly I:C (viral mimic) produces an acute inflammation, while LPS (bacterial endotoxin) produces chronic inflammation when exposed during early neonatal life.
Insights
Polyinosinic:polycytidylic acid (Poly I:C) causes acute inflammation, while lipopolysaccharide (LPS) causes chronic inflammation in neonatal rats. These immune responses differ in duration and intensity within the hippocampus.
Area of Science:
- Neuroscience
- Immunology
- Developmental Biology
Background:
- Neonatal exposure to immune stimuli can have long-lasting effects on brain development.
- Microglia and astrocytes are key immune cells in the central nervous system.
- Polyinosinic:polycytidylic acid (Poly I:C) mimics viral infections, while lipopolysaccharide (LPS) is a bacterial endotoxin.
Purpose of the Study:
- To compare the inflammatory effects of Poly I:C and LPS in the developing rat brain.
- To investigate the temporal dynamics of microglial and astrocytic activation following neonatal immune challenge.
Main Methods:
- Sprague Dawley rats were administered Poly I:C or LPS intraperitoneally during the neonatal period.
- Microglial and astrocytic activation was assessed in the hippocampus up to postnatal day 21 and beyond.
- Quantitative analysis of immune cell activity was performed.
Main Results:
- Both Poly I:C and LPS induced microglial and astrocytic activation in the hippocampus.
- Poly I:C resulted in higher immune cell activity until postnatal day 21 compared to LPS.
- LPS-induced inflammation persisted beyond postnatal day 21, unlike the Poly I:C response.
Conclusions:
- Neonatal exposure to Poly I:C induces acute hippocampal inflammation.
- Neonatal exposure to LPS induces chronic hippocampal inflammation.
- The type of immune challenge during early life dictates the duration and pattern of neuroinflammation.
