Expression of IL-1β in supraspinal brain regions in rats with neuropathic pain

• Published in: Neuroscience letters 2006-10, Vol.407 (2), p.176-181
• Main Authors: Vania Apkarian, A., Lavarello, Simona, Randolf, Anke, Berra, Hector H., Chialvo, Dante R., Besedovsky, Hugo O., del Rey, Adriana
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Brainstem; Chronic pain; Cranial nerves. Spinal roots. Peripheral nerves. Autonomic nervous system. Gustation. Olfaction; Cytokines; Fundamental and applied biological sciences. Psychology; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Prefrontal cortex; Thalamus; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2006.08.034

We examined mRNA expression of the pro-inflammatory cytokine IL-1β in the brainstem, thalamus, and prefrontal cortex in two rat models of neuropathic pain. Rats received a neuropathic injury: spared nerve injury (SNI) or chronic constriction injury (CCI), sham injury, or were minimally handled (control). Neuropathic pain-like behavior was monitored by tracking tactile thresholds. SNI-injured animals showed a robust decrease in tactile thresholds of the injured foot, while CCI-injured animals did not show tactile threshold changes. Ten or 24 days after nerve injury, IL-1β gene expression in the brain was determined by RT-PCR. IL-1β expression changes were observed mainly at 10 days after injury in the SNI animals, contralateral to the injury side, with increased expression in the brainstem and prefrontal cortex. The results indicate that neuro-immune activation in neuropathic pain conditions includes supraspinal brain regions, suggesting cytokine modulation of supraspinal circuitry of pain in neuropathic conditions.