Expression of IL-1beta in supraspinal brain regions in rats with neuropathic pain.
We examined mRNA expression of the pro-inflammatory cytokine IL-1beta 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-1beta gene expression in the brain was determined by RT-PCR. IL-1beta 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.
Apkarian
A Vania
AV
Department of Physiology, Northwestern University, Feinberg School of Medicine, 303 East Chicago Ave., Chicago, IL 60611, USA. a-apkarian@northwestern.edu
Lavarello
Simona
S
Randolf
Anke
A
Berra
Hector H
HH
Chialvo
Dante R
DR
Besedovsky
Hugo O
HO
del Rey
Adriana
A
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D017931:DNA Primers; D005456:Fluorescent Dyes; D007839:Functional Laterality / Q000502:physiology; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis / Q000235:genetics; D007375:Interleukin-1 / Q000096:biosynthesis*; D008297:Male; D010146:Pain / Q000209:etiology / Q000378:metabolism*; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000378:metabolism*; D010812:Physical Stimulation; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011921:Rats, Inbred WKY; D012684:Sensory Thresholds / Q000502:physiology
D017931:DNA Primers; D005456:Fluorescent Dyes; D007375:Interleukin-1; D012313:RNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases