Understanding how hibernation affects neurons sheds light on how neurons adapt to changing states and can inform treatment strategies for conditions in which neurons are damaged or impaired. In a new JNeurosci paper, researchers led by Hendrikje Nienborg, from the National Eye Institute, used squirrels to assess how hibernation alters neuron structure in a brain area that responds to visual information from the eyes. Why focus on this visual brain area? According to Nienborg, research shows strong neuron structure changes from hibernation in a part of the brain that processes touch, and these findings led to assumptions that neuron changes were happening in the visual brain as well.
The researchers assessed how two types of neurons in the visual brain area were affected during different stages of hibernation: deep sleep and an arousal stage that periodically occurs. One of the neuron populations had altered structure during deep hibernation compared to nonhibernating squirrels, while the other neuron population was unchanged. These effects reversed within 1.5 h after the animals aroused from deep hibernation. The researchers further assessed changes six months after hibernation and discovered there were no neuron structure differences between hibernating and nonhibernating squirrels.
Nienborg looks forward to taking this work further by exploring how neuron function changes during and after hibernation: "We know these structural changes have implications for neural communication, learning, and recovery after conditions like stroke. To see that there is a mechanism in the brains of these hibernating animals that [is so quick to change] is exciting because if we can figure out how to leverage this mechanism, we can potentially help human adult brains be more [adaptable] too, especially during recovery after stroke. We know a lot about how brain areas support visual processing, so exploring functional changes in the visual brains of squirrels is a very likely next step."
