據美國媒體每日科學消息,,這一研究能使我們更好地了解神經系統(tǒng)的發(fā)展及損害后神經細胞再生的過程。英國生物技術與生物科學研究理事會為此項研究投入了32萬歐元的研究經費,。
英國研究理事會成員,、萊斯特大學細胞生理與藥理學博士Volko Straub領導的這個研究項目也為一氧化氮為何在許多認知方面起如此重要作用給出了新的見解。Straub說:“一氧化氮氣體具有兩面性,,一是它有較高毒性,,對人體有害。但它也確實在大腦中自然地存在著,,被神經細胞用來進行細胞間的交流,。因此,一氧化氮即有毒性也可以用其有益一面作為信號傳遞,。”
“在大腦發(fā)育過程中,,一氧化氮對神經細胞的生長以及神經細胞間聯系的形成有促進作用。認知對神經細胞間形成新的聯系也有推動作用,,許多情況下需要一氧化氮的幫助,。”
盡管對一氧化氮在形成神經細胞連接的重要性有了認識,但科學家對其機制還了解不多,。這項計劃的目的是研究一氧化氮在神經細胞生長中的作用與神經細胞連接形成之間的關系,。
Straub解釋說:“在高等動物中研究這些作用和關系會因這些動物神經系統(tǒng)的復雜性而使研究面臨困難。幸好進化為我們幫了忙,,我們決定利用普通蝸牛的神經系統(tǒng),,它明顯沒有像高級動物,如小鼠那樣復雜的神經系統(tǒng),。
“蝸牛的神經細胞相對較大而且好識別,,易于操作。蝸牛的神經元被從神經系統(tǒng)中分離出來,,并進行細胞培養(yǎng),,使其能生長和形成功能上的連接。對神經細胞生長和形成功能連接起作用的基本程序和因子在所有動物中都完好保留了下來,。”
研究結果將會證明一氧化氮在神經細胞生長和形成功能連接上會發(fā)揮什么樣的作用,。從廣泛意義上來說,研究結果將會加深對神經生長和形成功能連接的一些因素的了解,。
部分英文原文:
Neural Modulation of Gut Motility by Myomodulin Peptides and Acetylcholine in the Snail Lymnaea
Families of peptide neuromodulators are believed to play important roles in neural networks that control behaviors. Here, we investigate the expression and role of one such group of modulators, the myomodulins, in the feeding system of Lymnaea stagnalis. Using a combination of in situ hybridization and antibody staining, expression of the myomodulin gene was confirmed in a number of identified behaviorally significant neuronal types, including the paired B2 motor neurons. The B2 cells were shown to project axons to the proesophagus, where they modulate foregut contractile activity. The presence of the five myomodulin peptide structures was confirmed in the B2 cells, the proesophagus, and the intervening nerve by mass spectrometry. Using a sensitive cell culture assay, evidence that the B2 cells are cholinergic also is presented. Application of four of the five myomodulin peptides to the isolated foregut increased both contraction frequency and tonus, whereas the main effect of acetylcholine (ACh) application was a large tonal contraction. The fifth myomodulin peptide (pQIPMLRLamide) appeared to have little or no effect on gut motility. Coapplication of all five myomodulin peptides gave a greater increase in tonus than that produced by the peptides applied individually, suggesting that corelease of the peptides onto the gut would produce an enhanced response. The combined effects that the myomodulin peptides and ACh have on foregut motility can mimic the main actions of B2 cell stimulation.