Local infusion of scopolamine into intraparietal cortex slows covert orienting in rhesus monkeys
Local infusion of scopolamine into intraparietal cortex slows covert orienting in rhesus monkeys
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DOI：
10.1152/jn.2000.83.3.1536
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发表时间：
2000-03-01
影响因子：
2.5
通讯作者：
Marrocco, RT
中科院分区：
文献类型：
--
作者：
Davidson, MC;Marrocco, RT
恒河猴顶叶内皮层局部注入东莨菪碱减缓内隐定向。神经生理学杂志。83：1536-1549，2000.越来越多的证据表明，胆碱能神经传递可能在视觉空间注意中发挥重要作用，但乙酰胆碱调节注意的大脑部位还没有得到很好的理解。目前的工作测试的假设，顶叶内皮层的胆碱能影响是必要的正常注意力转移（隐蔽定向）在非人灵长类动物。两只恒河猴被训练来执行用于液体强化的视觉、线索目标检测任务。动物按下杠杆产生视觉显示，其中一个中心固定点两侧是两个圆圈。在固定建立后不久，其中一个圆圈变亮（提示），随后一个目标出现在其中一个圆圈内。通过手动响应发出检测信号，并记录目标出现的反应时间。提出了四种类型的试验。对于有效线索实验，线索和目标在相同的空间位置;对于无效线索，线索和目标在相反的半野;对于双重线索，两个线索都变亮，但目标出现在左或右圈;在无线索实验中，线索被省略。我们用脑内微电极记录与注意力相关的细胞活动，定位顶叶内区域。在这一区域的视觉反应细胞中，有效的线索呈现给视觉神经元的感受野，增强了约一半的细胞对目标刺激的反应，抑制了其余细胞的反应。此外，一些细胞表现出更长的反应延迟无效的线索比有效的线索。然后，我们将东莨菪碱注入注意力相关的活动部位，并评估其对性能的影响。东莨菪碱产生了剂量依赖性的反应时间增加和性能的准确性，持续超过1小时的下降。在相同部位注射溶媒或生理学定义区域外注射东莨菪碱均未导致行为发生任何显著变化。在我们的测量条件下，我们的结论是，由顶内皮层的毒蕈碱胆碱能受体介导的活动是必要的正常的隐蔽定向。
Local infusion of scopolamine into intraparietal cortex slows covert orienting in rhesus monkeys. J. Neurophysiol. 83: 1536-1549, 2000. There is accumulating evidence to suggest that cholinergic neurotransmission may play an important role in visuospatial attention, but the brain sites at which acetylcholine modulates attention are not well understood. The present work tested the hypothesis that the cholinergic influences within the intraparietal cortex are necessary for normal attentional shifting (covert orienting) in nonhuman primates. Two rhesus monkeys were trained to perform a visual, cued target detection task for liquid reinforcement. The animals pressed a lever to produce a visual display in which a central fixation point was flanked by two circles. Shortly after fixation was established, one of the circles brightened (cue), and a target appeared subsequently within one of the circles. Detection was signaled by a manual response and the reaction time to the appearance of the target was recorded. Four types of trials were presented. For valid cue trials, the cue and target were at the same spatial location; for invalid cues, cue and target were in opposite hemifields; for double cues, both cues were brightened but the target appeared in either the left or right circle; in no-cue trials, the cue was omitted. We localized the intraparietal region by recording attention-related, cellular activity with intracerebral microelectrodes. Among visually responsive cells in this area, valid cues presented to the receptive fields of visual neurons enhanced the responses to target stimuli in about half the cells and inhibited those responses in the remainder. In addition, some cells showed longer response latencies to invalid cues than to valid cues. We then infused scopolamine into attention-related activity sites and assessed its effect on performance. Scopolamine produced a dose-dependent increase in reaction times and decrease in performance accuracy that lasted more than 1 h. Neither vehicle injections in the same locations nor scopolamine outside the physiologically defined area produced any significant change in behavior. Under our conditions of measurement, we conclude that activity mediated by muscarinic cholinergic receptors within the intraparietal cortex is necessary for normal covert orienting.