A single administration of ethanol simultaneously increases c-fos mRNA and reduces c-jun mRNA in the hypothalamus and hippocampus.
We have previously demonstrated that a single administration of ethanol induces the expression of c-fos mRNA in the hypothalamic paraventricular nucleus (PVN). However, Fos protein must interact with a member of the Jun family to form functional heterodimers. To determine whether ethanol may have differential effects on c-fos and c-jun expression, we injected male rats acclimated to a 25 degrees C environment with ethanol (3 g/kg b.wt.) or saline. Using in situ hybridization histochemistry with oligonucleotide probes, we found that ethanol increased c-fos mRNA in the PVN, but decreased c-jun mRNA both in the PVN and in hippocampus. Considering that ethanol produces hypothermia and that the PVN contains neurons activated during hypothermia, we evaluated the effect of cold on c-fos and c-jun mRNA. Both cold and ethanol increased c-fos mRNA, and the effects were additive. However, c-jun mRNA levels in both PVN and hippocampus were unaffected by temperature. Finally, c-jun mRNA levels in the hippocampus were significantly reduced by chronic ethanol exposure, and this trend was also observed in the PVN. These findings demonstrate that a single injection of ethanol has opposite effects on the expression of nuclear transcription factors which interact to regulate gene expression in the nervous system.
Department of Anatomy and Neurobiology, University of Missouri-Columbia School of Medicine 65212.
R T
RT
Zoeller
D L
DL
Fletcher
D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D000431:Ethanol / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D016762:Genes, fos / Q000187:drug effects*; D016758:Genes, jun / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D013462:Sulfur Radioisotopes
D015345:Oligonucleotide Probes; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D013462:Sulfur Radioisotopes; D000431:Ethanol