醫學院: 分子醫學研究所指導教授: 李秀香; 何奕倫;吳君泰鄭雅貞Cheng, Ya-ChenYa-ChenCheng2017-03-022018-07-092017-03-022018-07-092015http://ntur.lib.ntu.edu.tw//handle/246246/271746在動物中，心臟不須經由意識即可自行跳動，且具備維持正常生理作用的重要功能。許多心臟疾病例如冠狀動脈心臟病或心房顫動等，其發生原因源自於心臟正常跳動的功能受損。另外，人類神經系統會調控心臟跳動速率變動的現象也是廣為人知，但目前此調控機制仍未相當清楚。藉由果蠅剛蛹化 0-1hr APF (After Puparium Formation)，其外皮仍呈半透明且身體已固定不動的特點，不經解剖即可直接觀察心跳。果蠅的心臟靠近背部呈長條管狀，因此稱為心管 (Cardiac Tube) 或背管 (Dorsal Vessel)。綜觀上述特點，果蠅非常適合提供我們用於研究神經種類對心跳速率 (Heart Rate, HR) 之間的調控關係。 為了解析神經系統對心臟跳動的影響，我們聚焦在果蠅剛蛹化APF 0-1hr時期，在25°C和29°C 兩種環境下心跳速率的變異程度。透過GAL4/UAS system將對溫度敏感的蛋白質 (shibirets , dTrpA1) 或對光敏感的離子通道 (ChR2, NpHR) 表現在特定神經種類中，藉此專一地增加或減少此類神經的活性。實驗結果發現利用GAL4/UAS system專一表現dTrpA1在果蠅剛蛹化0-1 hr APF的廣泛神經 (Pan-neuron) 中，會顯著提升心跳速率改變量 (∆HR)。另一方面使用dTrpA1突變型-shibirets (突變後對溫度敏感)，以GAL4/UAS system專一表現shibirets在果蠅剛蛹化APF 0-1hr的廣泛神經中降低其神經活性，會顯著減少心跳速率改變量。增加膽鹼性神經元 (Cholinergic Neurons) 活性對心跳速率改變量無顯著影響，但減少膽鹼性神經元活性明顯降低心跳速率改變量。然而不論降低或增加glutamatergic neurons活性，其心跳速率改變量均不受影響。另外我們也針對心跳規律度 (Heart Rhythm) 各種異常心跳速率，包含心跳弛緩 (Slower HR, Bradycardia)、心跳過速 (Faster HR, Tachycardia)、心跳停止 (Pause) 進行分析。發現降低廣泛神經活性會減少心跳過速但會提高心跳弛緩的個體數，但增加其活性心跳規律度不會受太大影響。減少膽鹼性神經元活性時，心跳過速現象顯著提升，增加此神經活性無任何不影響。減少glutamatergic neurons活性明顯提升pause現象，但增加此神經活性則無影響。 綜觀上述結果，推測在果蠅剛蛹化0-1hr APF時，廣泛神經中存在某類群的神經可調控心跳速率，其中膽鹼性神經元為主要負責維持正常心跳速率以及維持正常心跳規律度的角色，而glutamatergic neurons則能保持心臟持續跳動。Cardiac automatism is critical for maintaining normal physiological function in animals. Several cardiac diseases, such as palpitations and atrial fibrillation, are caused by impairment of this process. Moreover, it has demonstrated that nervous system regulates cardiac automatism in human. However, the underlying mechanism of this regulation is unclear. The transparent surface of Drosophila at 0-1 hr APF (After Puparium Formation) makes it easy to directly examine the heart beating. The tubular-shaped dorsal vessel represents heart; therefore, it is plausible and suitable for us to identify how neurons regulate cardiac automatism. To examine the influence of nervous system on heart beating, we focused on the heart rate difference between 25°C and 29°C in Drosophila at 0-1 hr APF. We took advantage of temperature-sensitive (shits, dTrpA1) or light-sensitive (ChR2, NpHR) genetic tools to acutely and specifically activate or inhibit target neurons in Drosophila by GAL4/UAS system. We found that activation of pan-neuron by dTrpA1 at 0-1 hr APF significantly accelerated the heart rate. On the contrary, inhibition of pan-neuron by shibire temperature-sensitive mutant slowed down the heart rate difference. Activating cholinergic neurons did not alter the heart rate difference, but inhibiting cholinergic neurons decreased the alteration of heart rate difference. However, activation or inhibition of glutamatergic neurons did not have effect on heart rate. Also, we focused on the heart rhythm. We found that when inhibiting pan-neuron enhaced the rate of slower HR and decreased the rate of faster HR. Otherwise, we found that when inhibiting cholinergic neurons caused abnormal heart rhythm, but activating cholinergic neurons did not alter heart rhythm. Moreover, inhibition of glutamatergic neurons decreased pause phenomenons, but activation of glutamatergic neurons did not work on heart rhythm. Together, these results suggested some neurons exist in pan-neuron may regulate heart beating rate. And cholinergic neurons may play role in regulating heart rate and regular heart rhythm in Drosophila at 0-1 hr APF. The function of glutamatergic neurons is to maintain the heart beat in Drosophila at 0-1 hr APF 0hr.2758736 bytesapplication/pdf論文公開時間: 2020/9/25論文使用權限: 同意有償授權(權利金給回饋學校)果蠅心管神經系統心跳速率膽鹼性神經元DrosophilaCardiac tubeNervous systemHeart rateCholinergic neurons[SDGs]SDG3thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/271746/1/ntu-104-R02448011-1.pdf