Diurnal rhythmic expression of the rhythm-related genes, rPeriod1, rPeriod2, and rClock , in the rat brain

High densities of the mRNA of three rhythm-related genes, rPeriod1 (rPer1), rPer2 , and rClock , which share high homology in Drosophila and mammals, are found in the rat hypothalamic suprachiasmatic nucleus (SCN). The SCN, however, is not the only brain region that expresses these genes. To understand the possible physiological roles of these rhythm-related genes, we examined expression of these genes in different brain regions at various time points in male Sprague--Dawley rats. Using semi quantitative in situ hybridization with 35 S-riboprobes to evaluate mRNA levels, the diurnal rhythmicity of rPer1, and rPer2 mRNA levels was found in the SCN, arcuate nucleus, and median eminence/pars tuberalis. Expression patterns of mRNA for rPer1 and rPer2 , however, were not similar in these brain regions. The rhythmicity in these brain regions was specific, because it was not observed in the cerebellum or hippocampus. Moreover, diurnal changes in rClock mRNA expression were not detected in any of the brain regions examined. These findings suggest that the different expression patterns observed for rPer1, rPer2 , and rClock mRNAs may be attributed to their different physiological roles in these brain regions, and support previous work indicating that circadian rhythms in the brain are widespread.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43939/1/11373_2004_Article_8176.pd

Les phéromones urinaires de mâles induisent une puberté précoce et une attraction olfactive chez la souris femelle

National audienc

Puberty acceleration in female mice: behavioural effects and neuroendocrine consequences

International audienc

Behavioural and neurobiological consequences of peripubertal exposure to male urinary odour in female mice

International audienc

Olfactory regulation of Kisspeptin neurons during exposure to puberty-accelerating male pheromones in female mice

International audienc

Régulation olfactive des neurones à kisspeptine chez la souris femelle exposée à des phéromones mâles accélérant la puberté

International audienc

Neuroendocrine and behavioral consequences of peripubertal exposition to male odor in female mice

International audienc