Appetitive learning, patterned alternation, and extinction in 10-d-old rats with non-lactating suckling as reward
Appetitive learning, patterned alternation, and extinction in 10-d-old rats with non-lactating suckling as reward
复制标题
以非哺乳期哺乳作为奖励的 10 日龄大鼠的食欲学习、模式交替和灭绝
作者：
A. Amsel;David R. Burdette;R. Letz
HUGHLINGS-JACKSON1表达了这样的观点：在个体发生过程中，负责抑制的神经中枢比负责兴奋的神经中枢发育得慢。从那以后，工作的假设是，后来发展的，系统发育上的“高级”神经中枢调节（抑制？）“低级”神经中枢的兴奋。这一观点有一些行为和生理上的支持。在晚熟哺乳动物中，海马和新皮层在发育中相对较晚才功能成熟2，特别是海马与行为抑制的表达有关3 - 5。在出生后的第3周和第4周，未断奶的大鼠似乎在需要抑制反应的任务中不够成熟；例如，他们缺乏被动回避学习和适应新刺激的能力。他们在兴奋性任务中的表现，如主动回避和接近食物，似乎没有那么缺乏。这些任务特异性缺陷与海马受损的成年动物相似。Campbell等人注意到大鼠后期发育的抑制中枢与个体发生过程中自发活动的下降之间的对应关系，并证明了精神药理学制剂和抑制系统特有的脑损伤在发育早期增加行为唤醒方面是无效的。在我们的实验室中，对断奶前大鼠的工具性食欲学习进行了实验，其中包括在17至20日龄的幼鼠中使用干食物颗粒作为强化剂。在这么小的动物身上，我们已经用类似于成年老鼠的程序证明了习得、灭绝、即时持续和长期持续。我们现在报告了两个实验，证明了10岁大鼠的行为可塑性，包括获得和随后的接近反应的消失，奖励是短暂吮吸麻醉的母鼠的机会。
HUGHLINGS-JACKSON1 has expressed the view that, during ontogenesis, neural centres responsible for inhibition develop more slowly than centres responsible for excitation. Since then, the working hypothesis has been that the later-developing, phylogenetically ‘higher’ neural centres act to regulate (inhibit?) the excitation of the ‘lower’ centres. There has been some behavioural and physiological support for this position. In altricial mammalian species the hippocampus and neocortex become functionally mature relatively late in development2, and the hippocampus, in particular, has been implicated in the expression of behavioural inhibition3–5. Preweanling rats, during weeks 3 and 4 of life, seem to lack maturity for tasks requiring suppression of responding; for example, they are deficient in passive avoidance6 learning and in habituating to novel stimuli7,8. Their performance in excitatory tasks, such as active avoidance9 and approach for food10, seems to be less deficient. These task-specific deficits resemble those shown in hippocampally lesioned adult animals11. Campbell et al. have noted the correspondence between later-developing inhibitory centres in the rat and the decline in spontaneous activity occurring during ontogenesis12, and have demonstrated that psychopharmacological agents13 and brain lesions14 specific to inhibitory systems are ineffective in increasing behavioural arousal early in development. In our laboratory, experiments on instrumental appetitive learning in preweanling rats have involved the use of dry food pellets as reinforcers in pups as young as 17 to 20 d of age. In animals as young as this, we have demonstrated acquisition, extinction, immediate persistence, and long term persistence using procedures that are similar to those for adult rats15–17. We now report two experiments demonstrating behavioural plasticity in the 10-d-old rat, involving acquisition and subsequent extinction of an approach response where reward is the opportunity to suck briefly from an anaesthetised mother rat.