Gene expression in brain Homer1a-expressing cells after sleep deprivation

To gain insight into the molecular changes of sleep need, this study addresses gene expression changes in a subpopulation of neurons selectively activated by sleep deprivation. Whole brain expression analyses after 6h sleep deprivation clearly indicate that Homer1a is the best index of sleep need, consistently in all mouse strains analyzed. Transgenic mice expressing a FLAG-tagged poly(A)-binding protein (PABP) under the control of Homer1a promoter were generated. Because PABP binds the poly(A) tails of mRNA, affinity purification of FLAG-tagged PABP proteins from whole brain lysates, is expected to co-precipitate all mRNAs from neurons expressing Homer1a. Three other activity-induced genes (Ptgs2, Jph3, and Nptx2) were identified by this technique to be over-expressed after sleep loss. All four genes play a role in recovery from glutamate-induced neuronal hyperactivity. The consistent activation of Homer1a suggests a role for sleep in intracellular calcium homeostasis for protecting and recovering from the neuronal activation imposed by wakefulness.

24

Maret S, Dorsaz S, Gurcel L, Pradervand S, Petit B, Pfister C, Hagenbuchle O, O'Hara BF, Franken P, Tafti M