Malloy Cole, Sifers Jacob, Mikos Angela, Samadi Aya, Omar Aya, Hermanns Christina, Cooper Robin L
Department of Biology and Center for Muscle Biology, University of Kentucky, 675 Rose Street, Lexington, KY, 40506, USA.
Department of Science, Alice Lloyd College, Pippa Passes, KY, 41844, USA.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2017 Oct;203(10):791-806. doi: 10.1007/s00359-017-1191-7. Epub 2017 Jun 13.
The Drosophila melanogaster heart has become a principal model in which to study cardiac physiology and development. While the morphology of the heart in Drosophila and mammals is different, many of the molecular mechanisms that underlie heart development and function are similar and function can be assessed by similar physiological measurements, such as cardiac output, rate, and time in systole or diastole. Here, we have utilized an intact, optogenetic approach to assess the neural influence on heart rate in the third instar larvae. To simulate the release of modulators from the nervous system in response to environmental influences, we have directed expression of channel-rhodopsin variants to targeted neuronal populations to assess the role of these neural ensembles in directing release of modulators that may affect heart rate in vivo. Our observations show that the activation of targeted neurons, including cholinergic, dopaminergic, and serotonergic neurons, stimulate the release of cardioactive substances that increase heart rate after the initial activation at both room temperature and in a cold environment. This parallels previous studies suggesting these modulators play a crucial role in altering heart rate when applied to exposed hearts and adds to our understanding of chemical modulation of heart rate in intact Drosophila larvae.
黑腹果蝇的心脏已成为研究心脏生理学和发育的主要模型。虽然果蝇和哺乳动物心脏的形态不同，但许多心脏发育和功能的分子机制是相似的，并且功能可以通过类似的生理测量来评估，如心输出量、心率以及收缩期或舒张期的时间。在此，我们采用了一种完整的光遗传学方法来评估三龄幼虫中神经对心率的影响。为了模拟神经系统响应环境影响而释放调节剂的过程，我们将通道视紫红质变体定向表达于特定的神经元群体，以评估这些神经集合体在指导可能影响体内心率的调节剂释放中的作用。我们的观察结果表明，包括胆碱能、多巴胺能和5-羟色胺能神经元在内的特定神经元的激活，会刺激在室温及寒冷环境下初始激活后能增加心率的心脏活性物质的释放。这与之前的研究一致，这些研究表明，当将这些调节剂应用于暴露的心脏时，它们在改变心率方面起着关键作用，并且增进了我们对完整果蝇幼虫心率化学调节的理解。
