Time of day differences in IL1beta and TNFalpha mRNA levels in specific regions of the rat brain.
Interleukin-1beta (IL1beta) and tumor necrosis factor-alpha (TNFalpha) are involved in several physiological functions regulated by brain. The current studies were performed to determine whether a diurnal rhythm of IL1beta and TNFalpha mRNAs, determined by real time RT-PCR, existed in specific brain regions linked to the functions of these cytokines. Rats were sacrificed 2 h after light onset (AM) and 1 h prior to dark onset (PM). IL1beta mRNA levels in the AM were significantly higher than those obtained from rats sacrificed in the PM in the prefrontal cortex, parietal cortex, amygdala/piriform cortex, ventral hippocampus, hypothalamus, nucleus tractus solitarius, and nucleus accumbens, but not in the dorsal hippocampus. Time-of-day differences in TNFalpha mRNA levels were observed in all these brain regions. These results support the hypothesis that TNFalpha and IL1beta have physiological roles within the brain.
Cearley
Cassia
C
Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, College of Veterinary Medicine, PO Box 646520, Pullman, WA 99164-6520, USA.
Churchill
Lynn
L
Krueger
James M
JM
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D007375:Interleukin-1 / Q000096:biosynthesis*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D007375:Interleukin-1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha