Exploring the mechanisms involved in sleep-dependent memory storage, a team of University of Michigan (U-M) cellular biologists found that RNAs associated with an understudied cell compartment in hippocampal neurons vary greatly between sleeping and sleep-deprived mice after learning.
Sara Aton, Associate Professor in the Department of Molecular, Cellular, and Developmental Biology, and James Delorme, a recent U-M neuroscience graduate student, hypothesized that both a learning event and subsequent sleep (or sleep loss) would impact mRNA translation. Most prior work on the effects of sleep on mRNAs have focused on transcripts in the neuronal cytosol. However, Drs. Aton and Delorme found that after learning, major changes in RNAs are instead present —almost exclusively— on ribosomes associated with neuronal cell membranes. These results have been published in the Proceedings of the National Academy of Sciences, in November 30, 2021.*
In this representation, the red background is the cytosol, and ribosomes are in light green. tRNAs are the purplish blue blobs. Some tRNAs are in the cytosol and others are bound to the green ribosomes. The mRNAs are represented in yellow. The thin purple strand coming out the other side of the ribosomes (and into the ER lumen) is the protein. The big thick black lines in the bottom left corner represents the lipid bilayer of the ER membrane. (Image credit: Sara Aton)