The Functional Connectivity of the Secondary Somatosensory Cortex of the Rat

大鼠次級觸覺皮層的聯絡網路

廖佳琦(Chia-Chi Liao) ； 嚴震東(Chen-Tung Yen)

《Acta Zoologica Taiwanica》 14卷2期 (2004/10) Pp. 123-124

https://doi.org/10.6576/AZT.2004.14.(2).17

摘要

本實驗以電生理記錄和順向神經追蹤劑的方法研究次級觸覺皮層(secondary somatosensory cortex; SII)的功能以及和其他腦區的神經聯絡網路。在初級觸覺皮層(primary somatosensory cortex; SI)以及SII同時記錄由刺激對側前腳所引起的反應時，發現SII的多細胞神經反應顯著的快於SI者，而且對於不同刺激強度Si和SII均有類似的神經反應變化趨勢。爲了更進一步的證明SI、SII平行處理觸覺神經訊息的推測，將順向神經追蹤劑Biotinylated Dextran Amine (BDA)以電泳的方式注入丘腦的腹後外側核(ventral posterolateral nucleus, VPL)中，發現VPL的神經元以單突觸平行投射至SI和SII，而且SII具有體位對應組成(somatotopy)的情形。由本實驗的電生理以及解剖學證據得知SI和SII具有平行處理觸覺訊號的功能。

關鍵字

大鼠 ； 電刺激 ； 順向神經追蹤劑 ； Biotinylated Dextran Amine BDA ； 次級觸覺皮層SII ； 腹後外側核VPL

並列摘要

Input and output connections of the secondary somatosensory cortex (SII) were studied using anterograde tracing and electrophysiological recordings. Paired multi-unit responses in the primary somatosensory cortex (SI) and SII were evoked by electrical stimulation of the contralateral forepaw. Response latency was significantly shorter in the SII than the in the SI. Intensity-response of the SII was similar to that of the SI. Anterograde tracer Biotinyl Dextran was applied in the ventral posterolateral nucleus (VPL) to delineate the interconnection among the major thalamic and cortical somatosensory areas. The results showed that SII was connected directly by VPL axon terminals and this connection was somatotopically organized. Based on the electrophysiological and anatomical data, we concluded that SI and SII are processing parallel somatosensory information.

並列關鍵字

rat ； electrical stimulation ； anterograde tracer ； Biotinylated Dextran Amine BDA ； secondary somatosensory cortex SII ； ventral posterolateral nucleus VPL