Hibernation and the Hypothalamus
The temperature drop and the subsequent energy conservation is the key to the biological success of hibernation. The state of torpor is, however, accompanied by other dramatic changes. During the winter some species of hibernator hardly touch food during their periodic arousals even though it is present. In contrast to this prolonged anorexia, they eat voraciously in the prehibernation stage and routinely achieve spectacular metabolic prosperity. Their body weights show corresponding fluctuations. Water intake generally parallels food intake. Reproduction does not normally occur in the winter, and there is a seasonal atrophy of the gonads and of various other glands. Kayser (1961) lists such endocrine changes and also weight loss as useful in characterizing a species as a hibernator.
KeywordsGround Squirrel Lateral Hypothalamus Preoptic Area Lateral Hypothalamic Area Attack Zone
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