Researchers for the first time have evidence that a select subset of neurons from the dentate gyrus and a subset of limbic cortices show activation or plasticity during the rapid eye movement stage of sleep, according to a study of gene expression levels in rats.
By comparing gene expression, functional neuroanatomy, and neurochemical lesions in control, rapid eye movement (REM) sleep–deprived, and REM sleep hypersomniac rats, Dr. Leslie Renouard and coauthors found that certain cortical structures – the dentate gyrus, claustrum, cortical amygdaloid nucleus, and medial entorhinal, anterior cingulate, and retrosplenial cortices – had increased markers of activation during REM sleep.
“It is tempting to propose that the changes in gene expression seen in the present study during REM sleep hypersomnia in a network of limbic cortical neurons play a crucial role in cognitive and emotional information processing,” the investigators wrote. “The results may pave the way for the identification of the function of REM sleep by means of behavioral and electrophysiological studies combined with local inactivation of the subcortical pathways revealed.”Read the full article here: Sci. Adv. 2015;1:e1400177 (doi:10.1126/sciadv.1400177).