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題 名 | 內耳之興奮毒性=Excitotoxicity in Inner Ear |
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作 者 | 劉殿楨; | 書刊名 | 中華民國耳鼻喉科醫學會雜誌 |
卷 期 | 32:2 1997.04[民86.04] |
頁 次 | 頁66-71 |
分類號 | 416.821 |
關鍵詞 | 穀胺酸; 興奮毒性; 內毛細胞; 傳入神經末梢腫脹; L-glutamate; Excitotoxicity; Inner hair cell; Swelling of afferent nerve terminals; |
語 文 | 中文(Chinese) |
中文摘要 | 興奮毒性 (excitotoxicity) 是由於穀胺酸 (L-glutamate) 過度刺激而引起的 神經元腫脹或死亡。在內耳中,內毛細胞所使用的神經遞質仍不確定,但最有可能的就是穀 胺酸。所以在內耳中也會有興奮毒性的發生。其表現最初是內毛細胞下的初級傳入神經樹突 的末梢腫脹, 進而可以引起螺旋神經節的死亡。 目前已知神經末梢上同時存在有 NMDA 及 non-NMDA 受體,此二種受體均可媒介內耳之興奮毒性。 臨床上,與這些病變可能有關的情 形包括: 噪音引起的內耳傷害,耳蝸缺氧,或「神經型」的老年性耳聾。 |
英文摘要 | Amino acid L-glutamate was first proposed as a neuroecitatory agent some thirty years ago, and appears to be one of the major excitatory neurotransmitters in the central nervous system. Besides its neuroexcitatory action, L-glutamate was also found to be neurotoxic. Excessive exposure to L-glutamate may kill the neuron. This phenomenon is called "excitotoxicity", since the neurons are literally "excited to death". Excitotoxicity has been considered to be associated with various pathology in the central nervous system such as ischemia, epilepsy and some neurodegenerative diseases. In the cochlea, L-glutamate is also the best candidate as the neurotransmitters between inner hair cells and the primary afferent neurons. The prsentation of excitotoxicity in the inner ear includes swelling of the afferent nerve terminals and death of the spiral ganglion cells. These toxicity is problably mediated by both NMDA and non-NMDA receptors. Clinically, noise trauma, cochlear anoxia and neural type presbycusis may have colse relationship with excitotoxicity. |
本系統中英文摘要資訊取自各篇刊載內容。