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c‐Fos expression in preoptic nuclei as a marker of sleep rebound in the rat
Author(s) -
Dentico Daniela,
Amici Roberto,
Baracchi Francesca,
Cerri Matteo,
Del Sindaco Elide,
Luppi Marco,
Martelli Davide,
Perez Emanuele,
Zamboni Giovanni
Publication year - 2009
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2009.06848.x
Subject(s) - preoptic area , endocrinology , creb , medicine , median preoptic nucleus , chemistry , suprachiasmatic nucleus , rapid eye movement sleep , hypothalamus , biology , neuroscience , electroencephalography , biochemistry , blood pressure , transcription factor , gene , renin–angiotensin system , subfornical organ
Thermoregulation is known to interfere with sleep, possibly due to a functional interaction at the level of the preoptic area (POA). Exposure to low ambient temperature ( T a ) induces sleep deprivation, which is followed by sleep rebound after a return to laboratory T a . As two POA subregions, the ventrolateral preoptic nucleus (VLPO) and the median preoptic nucleus (MnPO), have been proposed to have a role in sleep‐related processes, the expression of c‐Fos and the phosphorylated form of the cAMP/Ca 2+ ‐responsive element‐binding protein (P‐CREB) was investigated in these nuclei during prolonged exposure to a T a of −10 °C and in the early phase of the recovery period. Moreover, the dynamics of the sleep rebound during recovery were studied in a separate group of animals. The results show that c‐Fos expression increased in both the VLPO and the MnPO during cold exposure, but not in a specific subregion within the VLPO cluster counting grid (VLPO T‐cluster). During the recovery, concomitantly with a large rapid eye movement sleep (REMS) rebound and an increase in delta power during non‐rapid eye movement sleep (NREMS), c‐Fos expression was high in both the VLPO and the MnPO and, specifically, in the VLPO T‐cluster. In both nuclei, P‐CREB expression showed spontaneous variations in basal conditions. During cold exposure, an increase in expression was observed in the MnPO, but not in the VLPO, and a decrease was observed in both nuclei during recovery. Dissociation in the changes observed between c‐Fos expression and P‐CREB levels, which were apparently subject to state‐related non‐regulatory modulation, suggests that the sleep‐related changes observed in c‐Fos expression do not depend on a P‐CREB‐mediated pathway.