Mapping parahippocampal systems for recognition and recency memory in the absence of the rat hippocampus
Mapping parahippocampal systems for recognition and recency memory in the absence of the rat hippocampus
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DOI：
10.1111/ejn.12740
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发表时间：
2014-12-01
影响因子：
3.4
通讯作者：
Aggleton, J. P.
中科院分区：
文献类型：
--
作者：
Kinnavane, L.;Amin, E.;Aggleton, J. P.
本研究检测了海马损伤大鼠嗅周皮质中即刻早期基因表达。目的是测试那些假设嗅周皮层可以独立于海马体发挥作用的识别记忆模型。靶向c-fos基因，因为其在嗅周皮质中的表达与识别记忆密切相关。对四组大鼠进行了检查。大鼠海马病变和他们的手术对照给予识别记忆任务（新的与熟悉的对象）或相对近的任务（熟悉程度不同的对象）。鼻周Fos表达与识别和近因表现相关。海马病变，但是，有没有明显的影响，对整体水平的嗅周或内嗅皮质c-fos的表达在响应新的对象，只有有限的影响被视为在近的条件。网络分析表明，而海马旁的相互作用的模式受到不同的影响，由新的或熟悉的对象，这些相关的网络没有改变海马病变。在对照组大鼠中的其他分析揭示了两种相关的内侧颞叶激活模式。新的刺激招募的途径，从外侧内嗅皮层（皮质层II或III）海马区CA 3，并从那里到CA 1。熟悉的刺激招募的直接途径从外侧内嗅皮层（主要是第三层）CA 1。目前的研究结果不仅揭示了一些与识别记忆相关的嗅周系统与海马的独立性，而且还显示了新的刺激如何以与熟悉的刺激不同的方式参与海马子场。
The present study examined immediate-early gene expression in the perirhinal cortex of rats with hippocampal lesions. The goal was to test those models of recognition memory which assume that the perirhinal cortex can function independently of the hippocampus. The c-fos gene was targeted, as its expression in the perirhinal cortex is strongly associated with recognition memory. Four groups of rats were examined. Rats with hippocampal lesions and their surgical controls were given either a recognition memory task (novel vs. familiar objects) or a relative recency task (objects with differing degrees of familiarity). Perirhinal Fos expression in the hippocampal-lesioned groups correlated with both recognition and recency performance. The hippocampal lesions, however, had no apparent effect on overall levels of perirhinal or entorhinal cortex c-fos expression in response to novel objects, with only restricted effects being seen in the recency condition. Network analyses showed that whereas the patterns of parahippocampal interactions were differentially affected by novel or familiar objects, these correlated networks were not altered by hippocampal lesions. Additional analyses in control rats revealed two modes of correlated medial temporal activation. Novel stimuli recruited the pathway from the lateral entorhinal cortex (cortical layer II or III) to hippocampal field CA3, and thence to CA1. Familiar stimuli recruited the direct pathway from the lateral entorhinal cortex (principally layer III) to CA1. The present findings not only reveal the independence from the hippocampus of some perirhinal systems associated with recognition memory, but also show how novel stimuli engage hippocampal subfields in qualitatively different ways from familiar stimuli.