日本帝京大学和北海道大学的研究人员发现,甲状腺激素有助于鸟儿进行印记学习。研究人员让刚刚孵化的雏鸡观察玩具鸡,结果发现雏鸡血液中的甲状腺激素大量进入大脑。而如果投放药物遏制雏鸡脑内的神经细胞与甲状腺激素结合,雏鸡则不再出现印记学习行为。研究人员还发现,雏鸡过了印记学习临界期后,如果向雏 Researchers at Teikyo University and Hokkaido University in Japan found that thyroid hormones help birds learn about imprinting. The researchers let the newly hatched chickens observe the toy chickens and found that a large amount of thyroid hormone in the chicken’s blood enters the brain. However, if the drug is administered to stop the neurons in the brain of the chicken from binding to the thyroid hormone, the chickens no longer have the imprint learning behavior. The researchers also found that chicks had impaled their learning threshold after a critical period