González-Mariscal G, Melo A I, Zavala A, Beyer C
Centro de Investigación en Reproducción Animal, Cinvestav-Universidad Autónoma de Tlaxcala, Mexico.
Physiol Behav. 1992 Nov;52(5):889-93. doi: 10.1016/0031-9384(92)90367-b.
Chin marking (chinning) frequency was determined daily in 25 male and 24 female New Zealand rabbits aged 31-150 days. Chinning appeared earlier in females (mean +/- SD = 41 +/- 16 days) than in males (47 +/- 13 days). Between days 30-50, females displayed chinning more frequently than males. Thereafter, chinning increased steadily in both sexes up to day 100. Chinning curves levelled on days 100 and 140 in males and females, respectively. Profile analysis of male and female chinning curves showed significant differences in their slopes and in their population means (p < 0.001). At 7 months of age (days 210-224), both sexes displayed adult chinning frequencies: mean of means +/- SD = 103 +/- 18 and 79 +/- 14 marks/10 min in males (n = 8) and females (n = 8), respectively. The administration of testosterone propionate (TP, 1 mg/day) or estradiol benzoate (EB, 1 microgram/day) to males and females, respectively, from days 31-50, stimulated higher chinning frequencies than those displayed by untreated animals. Results suggest that chinning frequency increases throughout development largely as a consequence of a concomitant increase in sex steroid secretion.
在25只31至150日龄的雄性新西兰兔和24只同龄雌性新西兰兔中，每天测定下巴标记（蹭下巴）频率。雌性出现蹭下巴行为的时间更早（平均±标准差=41±16天），早于雄性（47±13天）。在30至50日龄之间，雌性蹭下巴的频率高于雄性。此后，两性的蹭下巴频率均稳步上升，直至第100天。雄性和雌性的蹭下巴曲线分别在第100天和第140天趋于平稳。对雄性和雌性蹭下巴曲线的轮廓分析显示，它们的斜率和总体均值存在显著差异（p<0.001）。在7月龄（第210至224天）时，两性均表现出成年后的蹭下巴频率：8只雄性兔平均为103±18次/10分钟，8只雌性兔平均为79±14次/10分钟。分别在31至50日龄给雄性和雌性兔注射丙酸睾酮（TP，1毫克/天）或苯甲酸雌二醇（EB，1微克/天），刺激产生的蹭下巴频率高于未处理动物。结果表明，在整个发育过程中，蹭下巴频率的增加主要是由于性类固醇分泌相应增加所致。
