Learning and mother-infant relationship based on the fetal memory in the newborn

母亲的腹毛被羊水和喷出的牛奶弄湿，在许多哺乳动物的最初乳头抓取反应之前刺激新生幼崽的口腔区域。新生的幼崽接受这些刺激，探测母亲的皮毛，搜索乳头，并将其连接起来。据推测，新生的幼崽记住了羊水的特征，并在出生后立即将熟悉的羊水与新的刺激--母乳--联系在一起，并对这些刺激做出反应。本研究的目的是探讨这些刺激物与剖宫产小鼠瞳孔运动的关系。小白鼠孕鼠的羊水和自然分娩的母亲的乳汁均保持在70℃。毛刷是由一名捐赠者雌性乳头周围收集的毛皮制成的。剖腹产三小时后，每只幼崽接受9分钟的测试。在基线训练中，观察了幼鼠的自发身体活动。在气味展示环节中，用羊水、母乳、生理盐水和蒸馏水浸湿的毛刷被展示在小狗的鼻子前面。在刺激过程中，用刷子刺激幼崽的口周区域，用毛刷和羊水刺激口周区域，使头部伸展和上下运动、嘴巴运动和后肢运动增加。第0天的母乳对这些运动有一点影响，但在第3天的母乳对这些运动没有特别的影响。提示胎儿期常见的羊水对新生儿定位和依恋母亲有重要作用，母乳作为一种新的刺激物，可能与羊水有关，对依恋产生影响。

Mother's ventral fur, wet with amniotic fluid and ejected milk, stimulates the oral area of the newborn pup before the initial nipple grasp response in many mammals. The newborn pup receives these stimuli, probes the mother's fur, searches the nipple, and attaches it. It is hypothetized that the newborn pup memorizes characteristics of amniotic fluid, and that it associates the familiar amniotic fluid with novel stimulus, mother's milk, immediately after birth and responds to these stimuli. The aim of this study was to investigate the relationship between these stimuli and body movements in the cesarean-delivered mouse pups.The amniotic fluid obtained from pregnant females of Slc : ICR mice and mother's milk from the naturally parturient mothers were kept at 70℃ until the experiment. The fur brush was made of fur collected from around the nipple area of a donor female. Three hours after cesarean delivery each pup was tested for 9 minutes. In the baseline session, spontaneous body movements of pups were observed. In the odor presentation session, the fur brush wet with amniotic fluid, mother's milk, saline, and distilled water, was presented in front of the pup's nose. In the stimulation session, the perioral area of pups was stimulated with the brush.When the perioral area was stimulated with the fur brush and amniotic fluid, head extension and up-down movements, mouth movement, and rearlimb movement increased. Mother's milk on Day 0 had a little effect on these movements, but that on Day 3 had no specific effect. It indicates that the amniotic fluid familiar in prenatal period plays an important role for newborns to locate and attach the mother, and that the mother's milk, a novel stimulus, would be associated with the fluid and have the effect on attachment.