Döbrössy M D, Svendsen C N, Dunnett S B
MRC Cambridge Centre for Brain Repair, University of Cambridge, England.
Brain Res Bull. 1996;41(3):159-65.
It has been previously shown that lesions of the dorsal striatum can disrupt performance on a variety of cognitive tasks related to prefrontal cortex function. In order to extend these studies, we have compared the effects of bilateral striatal lesions on retention of an operant test of short-term memory using a delayed matching to position task. Rats were initially pretrained on the matching task. Then, one group of animals received ibotenic acid lesions in the dorsal striatum and a second group received sham lesions. The striatal lesions induced marked deficits on delayed matching performance when the rats were retested one week following surgery. The delay-independent pattern of deficit observed does not suggest a primary impairment in short-term memory function. The lesion induced deficits were temporary, with recovery seen in the lesion group back to a control level of performance in 2 additional test sessions 5 and 10 weeks post-lesion. A follow up study investigating the time course of the deficit suggests that the recovery seen in performance measures cannot be attributed to the elapse of time per se, but rather is due to re-learning. In addition to the performance deficits in the operant task, the lesioned rats exhibited marked nocturnal locomotor hyperactivity. The results indicate that bilateral striatal lesions induce marked deficits in retention of the delayed matching to position task. They suggest a key role for the neostriatum in the execution of pre-learned responses, but do not exclude the possibility of additional involvement in short-term memory functions under certain testing conditions.
先前的研究表明，背侧纹状体损伤会干扰与前额叶皮层功能相关的各种认知任务的表现。为了拓展这些研究，我们使用延迟位置匹配任务，比较了双侧纹状体损伤对操作性短期记忆测试保持能力的影响。大鼠最初在匹配任务上进行预训练。然后，一组动物接受背侧纹状体的鹅膏蕈氨酸损伤，另一组接受假损伤。当大鼠在手术后一周重新测试时，纹状体损伤导致延迟匹配表现出现明显缺陷。观察到的与延迟无关的缺陷模式并不表明短期记忆功能存在原发性损伤。损伤导致的缺陷是暂时的，在损伤后5周和10周的另外两次测试中，损伤组的表现恢复到了对照水平。一项调查缺陷时间进程的后续研究表明，表现测量中的恢复不能归因于时间的流逝本身，而是由于重新学习。除了操作性任务中的表现缺陷外，损伤大鼠还表现出明显的夜间运动活动亢进。结果表明，双侧纹状体损伤会导致延迟位置匹配任务保持能力出现明显缺陷。它们表明新纹状体在执行预先学习的反应中起关键作用，但不排除在某些测试条件下对短期记忆功能有额外参与的可能性。
