Suffolk Reporter

Research conducted at Stony Brook University has shed light on the unique adaptation of the Eurasian common shrew, which alters its brain and body size seasonally. Led by Postdoctoral Associate William Thomas and Professor Liliana Dávalos from the Department of Ecology and Evolution, the study was published in eLife.

The research focuses on Dehnel’s phenomenon, where the shrew's brain, skull, and organs shrink by up to 30% during winter to conserve energy. Unlike other small mammals that hibernate or migrate, the shrew remains active through this adaptive size change.

Thomas explained that they investigated gene expression in the hypothalamus—a brain region regulating energy balance—across seasons and species. "We generated a unique data set," said Thomas. "We found a suite of genes that change across the seasons involved in regulation of energy homeostasis."

Key findings include upregulated genes related to maintaining the blood-brain barrier and calcium signaling in shrews compared to other mammals. These changes may help manage energy demands efficiently.

Genes linked to human neurological disorders were also examined. CCDC22, crucial for protein recycling within cells, varied seasonally in shrews. Its regulation might offer neuroprotective benefits during brain mass restoration.

Thomas noted that chronic metabolic dysfunction is often associated with neurological diseases in humans. Insights from this study could eventually inform strategies for reversing similar changes as humans age.

Future research will continue exploring physiological changes associated with brain size using MRI and gene expression atlases developed for shrews. The team also plans further studies comparing gene evolution between shrews and other mammals.

This international collaboration includes researchers from institutions such as Max Planck Institute of Animal Behavior and University Medical Center Freiburg. Funding was provided partly by Human Frontiers of Science Program and a Presidential Innovation award to Dávalos from Stony Brook University.