Université de Fribourg

Lack of Food Anticipation in Per2 Mutant Mice

Feillet, Céline A. ; Ripperger, Jürgen A. ; Magnone, Maria Chiara ; Dulloo, Abdul G. ; Albrecht, Urs ; Challet, Etienne

In: Current Biology, 2006, vol. 16, no. 20, p. 2016-2022

Predicting time of food availability is key for survival in most animals. Under restricted feeding conditions, this prediction is manifested in anticipatory bouts of locomotor activity and body temperature. This process seems to be driven by a food-entrainable oscillator independent of the main, light-entrainable clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus 1 and 2....

Université de Fribourg

The opioid fentanyl affects light input, electrical activity and Per gene expression in the hamster suprachiasmatic nuclei

Vansteensel, Mariska J. ; Magnone, Maria Chiara ; Oosterhout, Floor van ; Baeriswyl, Stéphanie ; Albrecht, Urs ; Albus, Henk ; Dahan, Albert ; Meijer, Johanna H.

In: European Journal of Neuroscience, 2005, vol. 21(11), p. 2958

The suprachiasmatic nuclei (SCN) contain a major circadian pacemaker, which is regulated by photic and nonphotic stimuli. Although enkephalins are present in the SCN, their role in phase regulation of the pacemaker is largely unknown. The opioid agonist fentanyl, a homologue of morphine, is an addictive drug that induces phase shifts of circadian rhythms in hamsters. We observed that these phase...

Université de Fribourg

Circadian expression of the clock gene Per2 is altered in the ruin lizard (Podarcis sicula) when temperature changes

Magnone, Maria Chiara ; Jacobmeier, Birgit ; Bertolucci, Cristiano ; Foà, Augusto ; Albrecht, Urs

In: Molecular Brain Research, 2005, vol. 133, p. 281-286

When exposed to the cold, the body temperature of the ruin lizard (Podarcis sicula), an ectothermic vertebrate, comes into equilibrium with that low environmental temperature. During this time, the behavioral output of the circadian clock, locomotor activity, disappears. We tested the activity of the circadian clockwork at low temperature (6 °C) by following the expression of one of its...

Université de Fribourg

The clock gene Per2 influences the glutamatergic system and modulates alcohol consumption

Spanagel, Rainer ; Pendyala, Gurudutt ; Abarca, Carolina ; Zghoul, Tarek ; Sanchis-Segura, Carles ; Magnone, Maria Chiara ; Lascorz, Jesús ; Depner, Martin ; Holzberg, David ; Soyka, Michael ; Schreiber, Stefan ; Matsuda, Fumihiko ; Lathrop, Mark ; Schumann, Gunter ; Albrecht, Urs

In: Nature Medicine, 2004, vol. 11, p. 35-42

Period (Per) genes are involved in regulation of the circadian clock and are thought to modulate several brain functions. We demonstrate that Per2Brdm1 mutant mice, which have a deletion in the PAS domain of the Per2 protein, show alterations in the glutamatergic system. Lowered expression of the glutamate transporter Eaat1 is observed in these animals, leading to reduced uptake of glutamate by...