Cholinergic Effects on the Neurons of the Rat Suprachiasmatic Nucleus
碩士 === 長庚大學 === 基礎醫學研究所 === 93 === The suprachiasmatic nucleus (SCN) is the master pacemaker in mammals, with two anatomically and functionally distinct divisions of dorsal (dSCN) and ventral SCN (vSCN). In the SCN, both muscarinc and nictonic cholinergic receptors have been shown to be present and...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2005
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| Online Access: | http://ndltd.ncl.edu.tw/handle/05452627226220672171 |
| Summary: | 碩士 === 長庚大學 === 基礎醫學研究所 === 93 === The suprachiasmatic nucleus (SCN) is the master pacemaker in mammals, with two anatomically and functionally distinct divisions of dorsal (dSCN) and ventral SCN (vSCN). In the SCN, both muscarinc and nictonic cholinergic receptors have been shown to be present and acetylcholine acts directly on SCN neurons.
In this study, I used the cell-attached recording technique to investigate the effects of cholinergic agents on the SCN neurons, focusing on the time-dependent responses of both dSCN and vSCN neurons. I found that cholinergic agents altered the spontaneous firing rate (SFR) and the effects exhibited a circadian rhythm. Comparing the response profiles of muscarine (Musc) and nicotine (Nict) to that of carbachol (CCh) indicated that the carbachol responses were most likely mediated by the mAChR such as M1-mAChR on the dSCN neurons. The cholinergic responses of dSCN and vSCN neurons were in a similar way. However, the muscarinic responses of dSCN and vSCN neurons differed during the early night and during the low and high concentration. These data suggested that cholinergic effects on the neurons of the SCN might play an important role.
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