Brasted P J, Humby T, Dunnett S B, Robbins T W
Medical Research Council Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, CB2 2PY, United Kingdom.
J Neurosci. 1997 Nov 15;17(22):8919-26. doi: 10.1523/JNEUROSCI.17-22-08919.1997.
Rats were trained in a specially designed, multichoice operant chamber on a visual choice reaction time task designed to assess performance on each side of the rat's body. The task required animals to sustain a nose poke in a central hole, until a brief light stimulus was presented in either of two holes that were located on the same side of the box. Once the rats were trained to perform the task to both sides independently they received unilateral injections of quinolinic acid into the dorsal striatum. Postoperatively, lesioned animals were impaired when performing the task on the side contralateral to the lesion. The time taken to initiate contralateral responses was increased. Contralateral responses were also exclusively biased toward the nearer of the two response locations, regardless of the location of the stimulus. This was interpreted as a specific impairment in generating responses in contralateral space. In contrast, no comparable deficit was seen when the animals performed the task on the side ipsilateral to the lesion. Additional postoperative challenges, in which response options were presented bilaterally, showed this response deficit to be defined in egocentric coordinates, with the severest response deficits for the most contralateral locations.
将大鼠置于一个专门设计的多选择操作性实验箱中，进行视觉选择反应时间任务训练，该任务旨在评估大鼠身体两侧的表现。该任务要求动物将鼻子保持在中央孔中，直到在位于箱子同一侧的两个孔中的任意一个出现短暂的光刺激。一旦大鼠被训练能够独立地在两侧执行任务，它们就会接受向背侧纹状体单侧注射喹啉酸。术后，受损动物在损伤对侧执行任务时表现受损。启动对侧反应所需的时间增加。对侧反应也完全偏向两个反应位置中较近的一个，而不管刺激的位置如何。这被解释为在对侧空间产生反应的特定损伤。相比之下，当动物在损伤同侧执行任务时，没有观察到类似的缺陷。额外的术后挑战，即双侧呈现反应选项，表明这种反应缺陷是以自我中心坐标定义的，对最对侧位置的反应缺陷最为严重。
