AJP - Regulatory, Integrative and Comparative Physiology, Vol 270, Issue 6 1240-R1243, Copyright © 1996 by American Physiological Society

ARTICLES

Gonadectomy in the spring reinstates hibernation in male golden-mantled ground squirrels

J. Dark, D. R. Miller and I. Zucker
Department of Psychology, University of California, Berkeley 94720, USA.

We tested the hypothesis that continued secretion of gonadal steroids is necessary to suppress hibernation in male golden-mantled ground squirrels in the weeks after the terminal arousal in spring. Juvenile and adult males were gonadectomized or sham gonadectomized 1 wk after the terminal arousal; 64% of castrated and none of the shamcastrated animals resumed hibernation. Latency to resumption of torpor was 9 +/- 2 days from the time of castration, and squirrels underwent 4.3 +/- 0.9 bouts before permanently regaining euthermia. Among squirrels that resumed hibernation, bout duration was significantly shorter and torpor was shallower after castration. Castration as late as 3 wk after the terminal arousal reinstated hibernation. We suggest that the terminal arousal of male squirrels in the spring is provoked by a steroid-independent mechanism similar to that operating earlier in the hibernation season; abandonment of hibernation is contingent on concomitant sustained increases in androgen secretion during the first few weeks of euthermia.

This article has been cited by other articles:

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