大鼠次級觸覺皮層的聯絡網路

Functional connectivity of the secondary somatosensory cortex of the rat

廖佳琦(Chia-Chi Liao)

指導教授 ： 嚴震東

國立臺灣大學/生命科學院/動物學研究研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01848

摘要

本實驗利用電生理以及神經解剖學的方法研究大鼠次級觸覺皮層(SII)和其他體感覺區域之間的聯絡網路。利用不同強度的電流對大鼠的前腳進行刺激後，在對側的初級觸覺皮層(SI)以及SII中同時記錄由刺激所引起的多神經元活性反應。實驗結果顯示SII中的反應起始時間顯著的較SI快，而且SII對於不同強度刺激所引起的反應趨勢和SI類似。在神經解剖學實驗將順向追蹤劑 Biotinylated Dextan Amine利用電泳的方式注射至視丘的腹尾外側核（VPL）、SI以及SII中。結果顯示SII、VPL以及SI三者之間以體位對應的方式互相連結。另外電生理定位的實驗結果也再次證明了SII的體位對應組成。在此研究中我們在大鼠頂葉側邊的大腦皮層中只有發現單獨一個體感覺區域。經由電生理以及神經解剖學證據，顯示SII和SI具有平行以及連續處理觸覺訊息的功能，而且SII具有體位對應的情形存在。

關鍵字

體位對應 ； 次級觸覺皮層 ； 初級觸覺皮層

並列摘要

In the present study, input and output connections of the secondary somatosensory cortex (SII) of the rat were examined using electrophysiological recordings and anterograde tracing experiments. Paired multi-unit responses in the primary somatosensory cortex (SI) and SII were evoked by applying electrical stimulation to the contralateral forepaw. The response latency was significantly shorter in the SII than that in the SI, while the intensity-response of the SII was similar to that of the SI. In separate experiments, the anterograde tracer, Biotinylated Dextran Amine, was injected in the ventral posterolateral nucleus (VPL), SI, and SII respectively, to delineate thalamocortical, corticothalamic, and corticocortical interconnections. The results showed that the VPL, SI, and SII are reciprocally and somatotopically connected. The somatotopic organization of the SII was further confirmed by an electrophysiological mapping study. Only one representation set in the lateral parietal cortex was found in this study. Based on the electrophysiological and anatomical data, we concluded that the SI and SII process somatosensory information in parallel and serial manners, and that the SII is somatotopically organized.

並列關鍵字

somatotopy ； SII ； SI

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