AUTHOR=Decker Michael J., Rye David B., Lee Shih-Yu , Strohl Kingman P.

TITLE=Paradoxical Sleep Suppresses Immediate Early Gene Expression in the Rodent Suprachiasmatic Nuclei

JOURNAL=Frontiers in Neurology

VOLUME=1

YEAR=2010

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2010.00122

DOI=10.3389/fneur.2010.00122

ISSN=1664-2295

ABSTRACT=<p>Light stimulates neuronal activity with subsequent expression of the protein product of the immediate early gene, <italic>c-fos</italic>, in the Suprachiasmatic Nuclei (SCN). Non-photic stimuli is also thought to modulate activity within the SCN. Here, we sought to determine the effects intrinsic stimuli, specifically, the states of sleep upon <italic>c-fos</italic> protein expression in the SCN. In 16 rats, <italic>c-fos</italic> protein expression was evaluated at a fixed time of 1600 h (subjective night), following 1 h of electroencephalographically defined sleep. During sleep, as the state of paradoxical sleep (PS) increased, <italic>c-fos</italic> protein expression decreased (<italic>r</italic> = −0.41, <italic>p</italic> &lt; 0.033). The PS-associated reduction of <italic>c-fos</italic> positive cells occurred equally between animals asleep in the light and those asleep in the dark. We propose a model whereby PS duration might function as a homeostatic-entraining mechanism to reduce neuronal activity within the SCN, and thereby modulate circadian rhythms during sleep.</p>