Sasaki Y, Murakami N, Takahashi K
Physiol Behav. 1984 Jul;33(1):105-9. doi: 10.1016/0031-9384(84)90020-9.
The critical period for the entrainment of circadian rhythm in blinded pups by a foster mother with a rhythm inverted to that of the natural mother was determined by a convenient method for the analysis of the circadian rhythm of drinking behavior. The pups, optically enucleated on day 1, were transferred to the foster mother at various ages, measured in days from birth, and raised until weaning. When the pups were transferred before 4 days of age, the drinking rhythm of the adopted pups was in phase with that of the blinded natural pups born of and raised by the foster mother. On the other hand, when the mother was exchanged after 10 days of age, the rhythm of the adopted pups was out of phase with that of the natural pups of the foster mother. Pups exchanged on 5 or 7 days of age showed inconsistent phase of rhythm, either being entrained by the foster or the natural mothers, or affected by both mothers. These results indicate that blinded pups must be adopted by the foster mothers earlier than day 4 for the foster mothers to fully entrain the circadian rhythm of blinded pups.
通过一种分析饮水行为昼夜节律的简便方法，确定了由节律与自然母亲相反的养母对失明幼崽昼夜节律进行同步调节的关键时期。在出生第1天进行了眼球摘除手术的幼崽，在出生后的不同天数（以出生天数计）被转移到养母处，并饲养至断奶。当幼崽在4日龄之前被转移时，被收养幼崽的饮水节律与由养母生育并抚养长大的失明自然幼崽的饮水节律同步。另一方面，当在10日龄之后更换母亲时，被收养幼崽的节律与养母的自然幼崽的节律不同步。在5或7日龄时更换的幼崽表现出节律相位不一致，要么被养母同步，要么被自然母亲同步，或者受到两位母亲的影响。这些结果表明，失明幼崽必须在4日龄之前被养母收养，养母才能完全同步失明幼崽的昼夜节律。
