Hibernate for health

Groundhogs, hedgehogs, bears, and other hibernating animals manipulate their body processes to survive the long winter—or the long summer, in the case of the fat-tailed lemur. Now scientists say the furry ones' deep sleep could teach us valuable information about:

• Keeping transplant organs viable. Squirrel organs stay healthy at cold temperatures for weeks.

• Protecting hearts from reperfusion. Animals don't experience cardiac damage during reperfusion when they wake from hibernation, unlike people after a heart attack.

• Fighting obesity. Hibernating mammals produce increased amounts of the appetite-killing hormone leptin before going into deep sleep.

• Avoiding diabetes. Hibernators don't develop the disease despite rapid pre-hibernation weight gain.

• Reversing brain damage from Alzheimer's disease. Hibernators periodically wake up and repair neural connections lost during torpor.