Adjuvant-induced arthritis induces c-Fos chronically in neurons in the hippocampus.
Chronic pain, sickness behaviors, and cognitive decline are symptoms in rheumatoid arthritis. In the adjuvant-induced arthritis Lewis rat model, we examined the dynamics of c-Fos expression in the hippocampus, a brain region important for these symptoms. Brain sections were stained for c-Fos using immunohistochemistry. c-Fos-positive nuclei were counted in CA1, CA2, CA3 and the dentate gyrus of the dorsal hippocampi from rats receiving no treatment or base-of-the-tail injections of (1 or 2) incomplete or complete Freund's adjuvant (low- or high-dose), (3), Mycobacterium butyricum cell wall suspended in saline, or (4) saline, and sacrificed 4, 14, 21, or 126days post-immunization. Disease severity was evaluated by dorsoplantar foot pad widths and X-ray analysis. We report sustained dose- and subfield-dependent c-Fos expression with arthritis, but transient expression in nonarthritic groups, suggesting long-term genomic changes in rheumatoid arthritis that may be causal for behavioral changes, adaptation to chronic pain and/or cognitive decline associated with disease.
Department of Human Anatomy and Pathology, Loma Linda University School of Medicine, Loma Linda, CA, United States.
Jeffrey L
JL
Carter
Cheri
C
Lubahn
Dianne
D
Lorton
Tracy
T
Osredkar
T C
TC
Der
Jill
J
Schaller
Stephen
S
Evelsizer
Schari
S
Flowers
Natalie
N
Ruff
Bethany
B
Reese
Denise L
DL
Bellinger
D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000503:physiopathology; D015870:Gene Expression; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D011917:Rats, Inbred Lew
D016760:Proto-Oncogene Proteins c-fos