Shapiro E G, Johanson I B
Behav Neural Biol. 1985 May;43(3):274-86. doi: 10.1016/s0163-1047(85)91619-x.
Normal and hyperthyroid rat pups received intraoral infusions of 0.25% quinine hydrochloride at 8, 10, 12, 14, or 16 days of age. Chin scraping and paw treading, aversive behaviors that adult rats show to quinine, emerged at 12 to 14 days in normal animals and were accelerated in hyperthyroid animals. Once these behaviors emerged, the hyperthyroid pups showed levels of both paw treading and chin scraping that were typical of controls several days older. Hyperthyroid and control pups did not differ in their intake of quinine at ages at which there were marked differences in chin scraping and paw treading. Other types of responses that pups show to aversive stimuli, such as paw treading. Other types of responses were not affected by the thyroid treatment. These findings suggest that the appearance of chin scraping and paw treading at 12-14 days of age in normal animals results from maturation of motor systems underlying these behaviors, and that this maturation can be accelerated by treatment with thyroid hormones.
正常和甲状腺功能亢进的幼鼠在8、10、12、14或16日龄时经口输注0.25%的盐酸奎宁。成年大鼠对奎宁表现出的厌恶行为——刮下巴和踩爪子，在正常动物中于12至14日龄时出现，而在甲状腺功能亢进的动物中出现得更早。一旦这些行为出现，甲状腺功能亢进的幼鼠表现出的踩爪子和刮下巴水平与比它们大几天的对照组典型水平相当。在刮下巴和踩爪子存在显著差异的年龄，甲状腺功能亢进的幼鼠和对照幼鼠在奎宁摄入量上没有差异。幼鼠对厌恶刺激表现出的其他类型反应，如踩爪子，不受甲状腺治疗的影响。这些发现表明，正常动物在12 - 14日龄时出现刮下巴和踩爪子行为是由于这些行为背后的运动系统成熟所致，并且这种成熟可以通过甲状腺激素治疗加速。
