Barrett B A, Rizzo T, Spear N E, Spear L P
Behav Neural Biol. 1984 Sep;42(1):23-32. doi: 10.1016/s0163-1047(84)90388-1.
Periadolescent rats exhibit a number of behavioral differences in comparison with younger or older animals. For instance, periadolescents tend to show enhanced acquisition of simple active avoidance tasks, but impaired acquisition of more complex appetitive and aversive discriminations. In this experiment, rats were trained on a simple passive avoidance task at one of three ages, as weanlings (25 days), periadolescents (35 days), or young adults (45 days). Training occurred in the presence of both a redundant discriminative stimulus and a specified, redundant contextual stimulus. The periadolescents did not differ from either younger or older rats in rate of learning the passive avoidance task. The retention performance of these animals was then tested following a change in either, neither, or both of the redundant cues. When a measure of performance that controls for baseline activity was used, it was observed that periadolescents were not disrupted by a change in the redundant discriminative stimulus, a cue change that clearly disrupted performance in 25- and 45-day-old animals, and tended to be more disrupted by the contextual change than younger or older rats. It is hypothesized that the alterations in performance exhibited by periadolescents may be related to an ontogenetic alteration in stimulus selection modulated by the catecholaminergic systems.
与年幼或年长的动物相比，青春期前后的大鼠表现出一些行为差异。例如，青春期前后的大鼠往往在简单主动回避任务的习得方面表现增强，但在更复杂的食欲和厌恶辨别任务的习得方面受损。在本实验中，大鼠在三个年龄段之一接受简单被动回避任务训练，即断奶期（25天）、青春期前后（35天）或年轻成年期（45天）。训练在同时存在冗余辨别刺激和特定冗余情境刺激的情况下进行。青春期前后的大鼠在学习被动回避任务的速度上与年幼或年长的大鼠没有差异。然后在冗余线索之一、两者都不改变或两者都改变后测试这些动物的记忆表现。当使用一种控制基线活动的表现指标时，观察到青春期前后的大鼠不会因冗余辨别刺激的改变而受到干扰，这种线索改变明显干扰了25日龄和45日龄动物的表现，并且与年幼或年长的大鼠相比，它们往往更容易受到情境变化的干扰。据推测，青春期前后的大鼠表现出的行为改变可能与儿茶酚胺能系统调节的刺激选择的个体发育改变有关。
