Facultad de Psicología, Universidad de Málaga, Campus Teatinos s/n, 29071 Málaga, Spain.
Soc Neurosci. 2010;5(5-6):422-40. doi: 10.1080/17470919.2010.503618.
Fully-fledged affective systems in mature animals are in part the result of the impact of infantile experience on brain development. The present experimental series examines whether tactile stimulation in infancy (early handling) influences rough-and-tumble play (R&T) throughout the juvenile period, using a testing regime of 17 days divided into five parts where handled (H) and nonhandled (NH) Wistar rats are assessed daily. In Parts 1 and 2 (age range at the start: 30-33 days) the objective is to study the amount of R&T that the rats are capable of exhibiting under varying lengths of social deprivation. In Part 3 (37-40 days) the objective is to determine whether familiarity with the experimental situation has independent or interactive effects with early handling. In Part 4 (40-43 days) the objective is to obtain evidence of the suppressing effects of an unexpected contextual change. In Part 5 (56-59 days) the objective is to study whether the effects of early handling can still be present at an age when R&T has practically vanished in NH rats. Results show that early handling invigorates R&T affecting pins (i.e., the most rewarding component) at the expense of dorsal contacts by enhancing play motivation in a specific manner, and that it is able to dilate the inverted-U developmental curve of this behavior, thereby providing strong evidence for a direct effect on the neuropsychological systems for play motivation.
成熟动物中成熟的情感系统部分是婴儿期经历对大脑发育影响的结果。本实验系列研究了婴儿期（早期处理）的触觉刺激是否会影响整个青少年期的追逐嬉戏（R&T），使用 17 天的测试方案分为五个部分，每天评估处理（H）和未处理（NH）Wistar 大鼠。在第 1 部分和第 2 部分（开始时的年龄范围：30-33 天），目的是研究大鼠在不同的社交剥夺时间下表现出的 R&T 量。在第 3 部分（37-40 天），目的是确定对实验情况的熟悉是否具有与早期处理独立或交互的影响。在第 4 部分（40-43 天），目的是获得意外的上下文变化的抑制作用的证据。在第 5 部分（56-59 天），目的是研究在 NH 大鼠的 R&T 几乎消失的年龄，早期处理的效果是否仍然存在。结果表明，早期处理通过以特定的方式增强游戏动机，使 R&T 更加活跃，从而影响到刺激（即最有奖励性的成分），而不是影响到背部接触，并且它能够扩大这种行为的倒 U 形发展曲线，从而为其对游戏动机的神经心理系统的直接影响提供了有力证据。
