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Updated: Jun 13, 2026
Induction of Maternal Immune Activation in Mice at Mid-gestation Stage with Viral Mimic Poly(I:C)
Published on: March 25, 2016
Poly I:C induced microglial activation impairs motor activity in adult rats
I K Patro1, Amit, M Shrivastava
1School of Studies in Neuroscience, Jiwaji University, Gwalior 474011, India. ishanpatro@rediffmail.com
Abstract:
Polyinosinic:polycytidic acid (poly I:C) is a synthetic double stranded RNA, which mimics with viral genome and mediates immune activation response similar to double stranded RNA virus infection into the brain. Microglial cells are the immune competent cells of the central nervous system having Toll like receptors-3 on their surface. Upon establishing that poly I:C infusion into the brain causes microgliosis by creating a viral infection model, the present study was designed to evaluate the effects of microglial activation following poly I:C infusion on motor activity. We infused 100 microl of 1% solution of Poly I:C in TBE buffer directly into the lateral ventricle and TBE buffer as vehicle to controls. A significantly higher microglial cell count as compared to control on 2, 3 and 7 days post infusion was recorded. Motor activity and microglial cell count was assessed in both controls and poly I:C infused rats on 1, 2, 3, 7, 14, 21 and 28 days post infusion. A significant decrease in motor activity and motor coordination occurred with respect to control. The results clearly demonstrate that microglial activation has a direct relevance with decreased motor activity. Findings could also have their importance in understanding the role of microglial cells on behavioral aspects in viral diseases.
Insights
Polyinosinic:polycytidic acid (poly I:C) triggers microglial activation in the brain, mimicking viral infection. This immune response significantly impairs motor activity and coordination in rats.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Polyinosinic:polycytidic acid (poly I:C) is a synthetic double-stranded RNA that simulates viral RNA, activating immune responses.
- Microglial cells, the brain's immune cells, express Toll-like receptor 3 (TLR3) and are activated by double-stranded RNA.
- Poly I:C infusion into the brain models viral infection, leading to microgliosis.
Purpose of the Study:
- To investigate the impact of poly I:C-induced microglial activation on motor activity and coordination.
- To establish a model of viral infection in the brain using poly I:C to study neuroinflammation.
Main Methods:
- Poly I:C (1% solution in TBE buffer) was infused into the lateral ventricle of rats.
- Control rats received TBE buffer infusion.
- Microglial cell counts and motor activity/coordination were assessed at multiple time points post-infusion (1-28 days).
Main Results:
- Poly I:C infusion led to a significant increase in microglial cell counts compared to controls on days 2, 3, and 7.
- Rats infused with poly I:C exhibited a significant decrease in motor activity and motor coordination.
- A direct correlation was observed between microglial activation and reduced motor function.
Conclusions:
- Microglial activation induced by poly I:C directly impairs motor activity and coordination.
- These findings highlight the role of microglial cells in behavioral changes during viral central nervous system infections.
- The study provides insights into the neuroinflammatory mechanisms affecting motor function.
