Swan H, Schätte C
Science. 1977 Jan 7;195(4273):84-5. doi: 10.1126/science.831261.
Extracts of subcortical brains from hibernating ground squirrels, when injected intravenously into rats, caused a mean decrease in oxygen consumption of 35 percent and a decline in body temperature of 5 degree C. The effects lasted from 75 minutes to 30 hours. Brain extracts of nonhibernating squirrels caused no significant changes in these parameters.