Related Experiment Video
Updated: Jul 11, 2025
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Characterization of spinal microglial activation in a mouse model of imiquimod-induced psoriasis
Fumihiro Saika1, Yohji Fukazawa2, Shiroh Kishioka3
1Faculty of Wakayama Health Care Sciences, Takarazuka University of Medical and Health Care, Wakayama 640-8392, Japan; Department of Physiological Sciences, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama 640-8156, Japan.
Abstract:
Although microglia are associated with chronic pain, the role of spinal microglia in the regulation of itch remains unclear. In this study, we characterized spinal microglial activation in a mouse model of imiquimod (IMQ)-induced psoriasis. Hypertrophic (activated) microglia were observed throughout the spinal cord after the topical application of IMQ. Furthermore, the mRNA expression of microglial markers and inflammatory mediators was upregulated. Ablation of itch-related sensory neurons using resiniferatoxin decreased itch-related scratching behavior and the number of hypertrophic microglia in the spinal dorsal horn. Conclusively, sensory neuron input may partially contribute to spinal microglial activation after IMQ application.
Insights
Spinal microglia activation occurs in mice with imiquimod-induced psoriasis. Sensory neuron input partially contributes to this activation, suggesting a link between neurons and glial cells in itch regulation.
Area of Science:
- Neuroscience
- Immunology
- Dermatology
Background:
- Microglia, immune cells in the central nervous system, are implicated in chronic pain.
- The specific role of spinal microglia in regulating itch is not well understood.
Purpose of the Study:
- To investigate spinal microglial activation in a mouse model of imiquimod (IMQ)-induced psoriasis.
- To explore the relationship between sensory neurons and spinal microglia in the context of itch.
Main Methods:
- Topical application of imiquimod (IMQ) to induce psoriasis-like skin inflammation and itch in mice.
- Characterization of spinal microglial activation using histological and molecular techniques.
- Ablation of itch-related sensory neurons using resiniferatoxin.
Main Results:
- Hypertrophic (activated) microglia were observed throughout the spinal cord following IMQ application.
- Increased mRNA expression of microglial markers and inflammatory mediators was detected.
- Sensory neuron ablation reduced both scratching behavior and the number of activated spinal microglia.
Conclusions:
- Spinal microglia are activated in response to IMQ-induced psoriasis.
- Sensory neuron input plays a partial role in spinal microglial activation.
- These findings suggest a contribution of spinal microglia to itch regulation, potentially mediated by sensory neurons.
