神經傳導物廣泛分佈於發育初期吳郭魚中樞神經系統，本論文主要針對發育過程的幼魚利用細胞培養、生化分析及分子生物技術，探討性荷爾蒙、溫度、神經傳導物對吳郭魚神經系統在發育階段的影響。結果發現在雌化時期（the critical period of feminization），雌二醇可以抑制白胺酸水解酵素活性並促進單胺基氧化酵素活性進而抑制血清素含量，此血清素系統活性的降低與吳郭魚雌化作用有密切相關，且雌化作用與發育初期腦中環化酵素與雌性素接受器ERa的基因表現量降低有關。而雄化作用則與雄化時期環化酵素與雌性素接受器ERb的基因表現量增加有關。環化酵素的活性則證實，處理以雌性素可抑制0至10天吳郭魚腦中環化酵素的基因表現以抑制其活性，在雄化臨界期則是雄性素具促進腦中環化酵素的基因表現以增加其活性。對神經細胞增生的實驗中證實，雌二醇可藉由Nongenomic pathway（細胞膜上的雌性素接受器）中的MAP kinase促使細胞的增生，另外血清素則可經由接受器5-HT1A及5-HT2促使神經細胞的增生。外在環境因子溫度則會影響吳郭魚中樞神經傳導物的發育，且在不同發育階段對不同的系統有不同作用。其對性別分化上的影響，雌化時期低溫類似雌二醇具雌化作用，雄化時期高溫則會雄化作用類似雄性素。且與性荷爾蒙間具有交互影響。綜合上述結果，外在環境因子溫度、內在因子如性荷爾蒙、神經傳導物等可影響發育初期吳郭魚中樞神經傳導物的發育，且對不同種神經傳導物系統具有不同的有效作用時期，各系統間並可互相調控，進而影響性別分化。

Neurotransmitters are widely distributed in the central nervous system of tilapia during development. In the present study, the effects of gonadal steroids, temperature, and neurotransmitters on the development of central neurotransmitter systems in tilapia, Oreochromis mossambicus, were investigated. Exogenous E2 before 10 days posthatching resulted in an inhibitory effect on the activity of central 5-HT system via decreasing TPH activity and increasing MAO activity, a decrease of the gene expression of brain aromatase and ERa, which is involved in the feminization. The masculinizing actions of 17a-methyltestosterone (MT) are most potent later at up to day 20 of age, and may depend on MT-induction of aromatase activity, aromatase mRNA gene expression and estrogen receptor-b mRNA gene expression. The development of central neurotransmitter systems is influenced by aquatic temperature during its respective restricted period. The influence of both lower and elevated temperatures on the neurotransmitter activity, either increasing or suppressing, is dependent on its developing stage. Neurotransmitters have an effect to influence the development of central neurotransmitter and this effect may mediated by the neural proliferation.

致謝辭----------------------------------------------------------I
論文提要------------------------------------------------------II
目錄------------------------------------------------------------V
圖表目錄-----------------------------------------------------VI
緒 論 ----------------------------------------------------------1
實驗主題------------------------------------------------------4
第一部分、性荷爾蒙對吳郭魚神經發育的影響-------5
第二部分、溫度對吳郭魚中樞神經系統的影響----- 30
第三部分、神經傳導物質對吳郭魚中樞神經及形態發育的影響 -------------------------------------48
結論-----------------------------------------------------------58
參考文獻-----------------------------------------------------59
附錄一（表、圖）-----------------------------------------63
附錄二--------------------------------------------------------91

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