Gene expression shifts help explain how a shrew changes brain size to match the seasons

New research shows how the Eurasian common shrew (Sorex araneus) changes its brain and bodily size throughout the year. The study, published online in eLife, reveals how changes in gene expression enable these small mammals to shrink their brain in winter and regrow it in spring, defying the typical mammalian pattern where organ size does not change. Their findings offer genetic clues to neurological and metabolic health in mammals.