Testosterone influences hibernation in golden-mantled ground squirrels.
At different phases of the hibernation season, castrated male golden-mantled ground squirrels were implanted with capsules that either were filled with testosterone (T) or left empty (blank). Blank-treated animals hibernated normally when housed at 5 degrees C. Entry into hibernation was prevented in the majority of squirrels treated with T several days before the initial cold challenge. T concentrations that inhibited torpor (greater than 1.2 ng/ml) were comparable with those of intact males at the end of the hibernation season. In some squirrels, moderate T concentrations were compatible with hibernation, but torpor bout duration was shorter than normal. The inhibitory effect of T on hibernation did not appear to require aromatization of T to estradiol. We suggest that a steroid-independent mechanism triggers arousal from hibernation and that T-dependent processes determine whether hibernation is resumed at the end of an arousal period.
Lee
T M
TM
Department of Psychology, University of California, Berkeley 94720.
Pelz
K
K
Licht
P
P
Zucker
I
I
D000818:Animals; D001831:Body Temperature; D006605:Hibernation / Q000502:physiology*; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D009919:Orchiectomy; D012589:Sciuridae / Q000502:physiology*; D012621:Seasons; D013686:Telemetry; D013739:Testosterone / Q000502:physiology*; D013997:Time Factors
D013739:Testosterone