FETAL LEARNING IN UTERO

心理生物学研究的一个明确含义是， 早期事件在塑造随后发展中的重要性。 对啮齿动物胎儿的观察和操作已经允许 调查产前行为发育的过程， 将学习和记忆的发展起源追溯到产前， 期 胎鼠模型优于新生儿研究， 因为胎儿缺乏与哺乳相关的刺激经验 或母性行为。 胎儿也可以维持在 实验设置，不需要积极的行为护理， 母亲 大鼠胎儿提供了一个简单的哺乳动物系统， 关于如何获得联想和记忆的实验研究 储存在一个不完整的神经系统中， 在个体发育早期迅速变化。 产前的感官体验是 通过对单个胎儿受试者的刺激来控制 在相对稳定的感官背景下 该提案介绍了 触觉和化学感觉刺激，模仿的重要特征， 新生儿环境，包括人工乳头和乳汁。 这些 刺激可靠地唤起幼稚动物行为和生理反应， 胎儿受试者，包括乳汁对胎儿阿片系统的激活， 并且可以通过它们的结合来支持胎儿学习。阿片活性 也可以通过施用选择性激动剂来操纵， 拮抗剂药物给个体胎儿受试者。 胎儿的反应 通过观察运动行为来测量，包括协调动作 模式. 物种典型的运动反应将作为行为 用于测量阿片样物质参与胎儿联合学习的生物测定 和记忆 本研究计划将调查（a） 条件反射的获得，（B）胎儿对 人工乳头，（c）条件反射对阿片类药物反应的影响 由乳汁诱发，（d）记忆和保留与乳头有关的经历， 和（e）胚胎学习中阿片类物质参与的个体发生变化。 的 使用生态相关和发展适当的感官 研究胎儿学习的操作提供了一种定量的手段， 评估发育中的神经系统的综合输出 完整的动物。

One of the clear implications of psychobiological research is the importance of early events in shaping subsequent development. Observation and manipulation of rodent fetuses has permitted investigation of the process of prenatal behavioral development, and has traced the developmental origins of learning and memory to the prenatal period. The fetal rat model presents advantages over neonatal study, because the fetus lacks experience with stimuli associated with suckling or maternal behavior. The fetus also can be maintained in an experimental setting that does not require active behavioral care by the mother. The rat fetus provides a simple mammalian system for experimental investigation of how associations are acquired and memories are stored within an incomplete nervous system that undergoes constant and rapid change during early ontogeny. Prenatal sensory experience is controlled by presentation of stimuli to individual fetal subjects against a relatively stable sensory background. This proposal introduces tactile and chemosensory stimuli that mimic important features of the neonatal environment, including an artificial nipple and milk. These stimuli reliably evoke behavioral and physiological responses from naive fetal subjects, including activation of the fetal opioid system by milk, and can support fetal learning through their association. Opioid activity also can be manipulated by administration of selective agonist and antagonist drugs to individual fetal subjects. Responses of the fetus are measured by observing motor behavior, including coordinated action patterns. Species-typical motor responses will serve as behavioral bioassays for measuring opioid involvement in fetal associative learning and memory. This program of research will investigate (a) the acquisition of conditioning, (b) the specificity of fetal responses to the artificial nipple, (c) effects of conditioning on opioid responses evoked by milk, (d) memory and retention of experiences with the nipple, and (e) ontogenetic changes in opioid involvement in fetal learning. The use of ecologically relevant and developmentally appropriate sensory manipulations to study fetal learning provides a means for quantitative assessment of the integrated output of the developing nervous system in the intact animal.