1. 1. Ground squirrels were chronically prepared for the determination of hypothalamic stimulus thresholds during hibernation at brain temperatures (Tbr) of 9-15°C by observations of heart rate (HR), neck muscle activity (EMG) and Tbr changes. 2. 2. Preliminary tests on euthermic squirrels showed that the hypothalamic sites were rewarding since animals self-stimulated the sites at a rate proportional to the stimulus intensity. 3. 3. During bouts of hibernation, the threshold for increased HR varied from 2- to 5-fold but did not vary significantly with Tbr or the percentage of the hibernation bout elapsed. 4. 4. Stimulation of the hypothalamus resulted in rises of Tbr during hibernation only if the stimulus produced cardioacceleration.
|Original language||English (US)|
|Number of pages||8|
|Journal||Comparative Biochemistry and Physiology -- Part A: Physiology|
|State||Published - 1981|
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