Shrew Brains Shrink During Winter Expand Again After Winter

Amazing stuff! What a life!

"... Instead [of hibernating], according to a study published November 30 in PNAS, in winter, these shrews lose 28 percent of the volume from their somatosensory cortex, which likely helps them conserve energy. ...
Scientists have shown before that red-toothed shrews, which belong to a group separate from the Etruscan shrew, are born and grow to their full body size in a single summer. Then in autumn, they start to shrink all over—in their spine length, skull, brain, bones, organs such as the liver, and body weight—reaching their smallest size in the winter. Somewhere around February, they start to grow again and reach a second size peak as they sexually mature in the spring. Then they reproduce just once, and, shortly after, die. This cycle is known as Dehnel’s phenomenon. ..."

"... Imaging of neural activity revealed reduced suppressive responses to whisker touch during winter, indicating that such cortical adaptation may have synergistic functional and behavioral effects in addition to direct metabolic benefits."

Shrew Brains Shrink During Winter | The Scientist Magazine® The animals kill off around one-quarter of the neurons in their somatosensory cortex, perhaps to save energy, and the cells appear to return the following summer.

Here is the link to the research paper:

Seasonal plasticity in the adult somatosensory cortex