Numan R, Quaranta J R
Department of Psychology, Santa Clara University, CA 95053.
Brain Res. 1990 Oct 29;531(1-2):232-41. doi: 10.1016/0006-8993(90)90779-b.
The septohippocampal system regulates spatial behavior, memory and response flexibility. This experiment determined which of these functions is disrupted by medial septal lesions which impair operant delayed alternation in rats. Male hooded rats received either medial septal lesions or a control operation. Following recovery, they were reinforced for alternating left and right lever presses in an operant chamber. The effects of various delays (0, 10 and 20 s), and exteroceptive cues were assessed. Medial septal lesions did not impair alternation performance at the 0-s delay, but did produce severe impairments at the 10- and 20-s delays. An exteroceptive light cue which reduced the spatial requirements of the task did not ameliorate this impairment. However, an exteroceptive light cue which reduced the working-memory requirements of the task did ameliorate the lesion-induced deficit on delayed alternation. While the lesioned rats also made more perseverative errors than the controls, statistically removing this influence from the data did not modify the results. These data suggest that medial septal lesions in rats impair operant delayed alternation by disrupting the general process of working-memory rather than spatial behavior or response flexibility.
隔海马系统调节空间行为、记忆和反应灵活性。本实验确定了大鼠内侧隔区损伤会损害操作性延迟交替，那么这些功能中的哪一项会受到破坏。雄性有帽大鼠接受内侧隔区损伤或对照手术。恢复后，它们在操作箱中因交替按压左右杠杆而得到强化。评估了各种延迟（0、10和20秒）以及外部感觉线索的影响。内侧隔区损伤在0秒延迟时不损害交替表现，但在10秒和20秒延迟时确实产生严重损害。一个减少任务空间要求的外部感觉光线索并不能改善这种损害。然而，一个减少任务工作记忆要求的外部感觉光线索确实改善了损伤引起的延迟交替缺陷。虽然损伤大鼠也比对照大鼠出现更多的持续性错误，但从数据中统计去除这种影响并没有改变结果。这些数据表明，大鼠内侧隔区损伤通过破坏工作记忆的一般过程而非空间行为或反应灵活性来损害操作性延迟交替。
