Common Shrews Shrink Their Brains to Survive Winter, Study Reveals
A fascinating new study has uncovered the incredible ability of the common shrew (Sorex araneus) to shrink its brain by 30 percent in preparation for winter, allowing it to conserve vital energy during the colder months. The research, which delves into the evolutionary origins of this unique adaptation, may hold promising implications for understanding and potentially treating human brain degeneration.
The phenomenon, known as Dehnel’s phenomenon after Polish zoologist August Dehnel who first documented it, is not exclusive to shrews. Other mammals such as European moles, common weasels, and stoats also exhibit brain size reduction as a response to seasonal energy shortages.
Leading the investigation, ecologist William Thomas from Stony Brook University spearheaded a comprehensive study mapping the entire genome of the common shrew. By comparing it to other species that display Dehnel’s phenomenon, the researchers identified key genetic markers that may play a role in enabling this extraordinary adaptation.
The study revealed that genes associated with brain cell creation were highly active in species that undergo brain size reduction. Specifically, the common shrew showed increased expression of VEGFA, a gene linked to blood-brain barrier permeability, DNA repair, and longevity.
Furthermore, genes related to water regulation were found to play a crucial role in the reversible brain volume reduction observed in shrews, indicating that the shrinkage is primarily due to water loss rather than cell death.
The researchers highlighted the intricate mechanism that allows common shrews to regulate brain shrinkage without experiencing the negative effects typically associated with neurodegeneration. This discovery opens up possibilities for identifying potential biomarkers and therapeutic targets for neurodegenerative diseases, although caution is advised when extrapolating findings to human biology.
Published in Molecular Biology and Evolution, this groundbreaking research sheds light on the remarkable adaptations of these tiny creatures and how they could inspire new avenues of research in the field of brain function and regeneration.
