Formation of mnemonic neuronal responses to visual paired associates in inferotemporal cortex is impaired by perirhinal and entorhinal lesions
Formation of mnemonic neuronal responses to visual paired associates in inferotemporal cortex is impaired by perirhinal and entorhinal lesions
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DOI：
10.1073/pnas.93.2.739
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发表时间：
1996-01-23
影响因子：
11.1
通讯作者：
Miyashita, Y
中科院分区：
文献类型：
--
作者：
Higuchi, S;Miyashita, Y
在执行视觉成对联想任务的猴子中研究了皮质后向信号在长期记忆形成中的功能作用，在猴子学习任务之前，前连合被横断，断开每个半球的前颞叶皮层，在用12对图片进行训练后，从猴子的颞下皮层记录单个单元作为对照，通过注射鹅膏酸网格，我们单侧损伤了大脑半球的前连合。内嗅和嗅周皮层，向颞下皮层同侧提供大量直接和间接向后投射，病变后，猴子正常固定提示刺激，重新学习术前学习的组（A组），并学习一组新的配对关联组（B组），然后，从与病变前对照相同的区域记录单个单元，我们发现（i）尽管存在病变，采样的神经元仍做出反应强烈且选择性地对 A 组和 B 组模式进行强烈且选择性的刺激，并且 (ii) 配对关联物在病变前的对照神经元中引起显着相关的反应，但在病变后测试的细胞中则没有，无论是 A 组刺激还是 B 组刺激。神经元对特定视觉刺激做出反应的能力保持完好。
Functional roles of the cortical backward signal in long-term memory formation were studied in monkeys performing a visual pair-association task, Before the monkeys learned the task, the anterior commissure was transected, disconnecting the anterior temporal cortex of each hemisphere, After training with 12 pairs of pictures, single units were recorded from the inferotemporal cortex of the monkeys as the control, By injecting a grid of ibotenic acid, we unilaterally lesioned the entorhinal and perirhinal cortex, which provides massive direct and indirect backward projections ipsilaterally to the inferotemporal cortex, After the lesion, the monkeys fixated the cue stimulus normally, relearned the preoperatively learned set (set A), and learned a new set (set B) of paired associates, Then, single units were recorded from the same area as for the prelesion control, We found that (i) in spite of the lesion, the sampled neurons responded strongly and selectively to both the set A and set B patterns and (ii) the paired associates elicited significantly correlated responses in the control neurons before the lesion but not in the cells tested after the lesion, either for set A or set B stimuli, We conclude that the ability of inferotemporal neurons to represent association between picture pairs was lost after the lesion of entorhinal and perirhinal cortex, most likely through disruption of backward neural signals to the inferotemporal neurons, while the ability of the neurons to respond to a particular visual stimulus was left intact.