Abstract

Optogenetics controls neural activity and behavior in living organisms through genetically targetable actuators and light. This method has revolutionized biology and medicine as it allows controlling cells with high temporal and spatial precision. Optogenetics is typically applied only at short time scales, for instance to study specific behaviors. Optogenetically manipulating behavior also gives insights into physiology, as behavior controls systemic physiological processes. For example, arousal and sleep affect aging and health span. To study how behavior controls key physiological processes, behavioral manipulations need to occur at extended time scales. However, methods for long-term optogenetics are scarce and typically require expensive compound microscope setups. Optogenetic experiments can be conducted in many species. Small model animals such as the nematode C. elegans have been instrumental in solving the mechanistic basis of medically important biological processes. We developed the OptoGenBox, an affordable stand-alone and simple-to-use device for long-term optogenetic manipulation of C. elegans. The OptoGenBox provides a controlled environment and is programmable to allow the execution of complex optogenetic manipulations over long experimental times of many days to weeks. To test our device, we investigated how optogenetically increased arousal and optogenetic sleep deprivation affect survival of arrested first larval stage C. elegans. We optogenetically activated the nociceptive ASH sensory neurons using ReaChR, thus triggering an escape response and increase in arousal. In addition, we optogenetically inhibited the sleep neuron RIS using ArchT, a condition known to impair sleep. Both optogenetic manipulations reduced survival. Thus, the OptoGenBox presents an affordable system to study the long-term consequences of optogenetic manipulations of key biological processes in C. elegans and perhaps other small animals.

摘要

光遗传学通过可遗传靶向的致动器和光来控制活生物体的神经活动和行为。这种方法彻底改变了生物学和医学方法，因为它可以控制高度的时间和空间精度的细胞。光遗传学通常仅在短时间内应用，例如研究特定行为。由于行为控制着系统的生理过程，因此光遗传学地操纵行为也可以使人们深入了解生理学。例如，唤醒和睡眠会影响衰老和健康期。为了研究行为如何控制关键的生理过程，需要在较长的时间范围内进行行为操纵。然而，用于长期光遗传学的方法很少，并且通常需要昂贵的复合显微镜设置。可以在许多物种中进行光遗传学实验。秀丽隐杆线虫一直在解决医学上重要的生物学过程的机制基础方面发挥了作用。我们开发了OptoGenBox，这是一种经济实惠的独立且易于使用的设备，可用于秀丽隐杆线虫的长期光遗传学操作。OptoGenBox提供了受控的环境，并且可以进行编程，以允许在数天至数周的长时间实验时间内执行复杂的光遗传学操作。为了测试我们的设备，我们调查了光遗传学增加的唤醒和光遗传学睡眠剥夺如何影响被捕的第一幼虫阶段秀丽隐杆线虫的存活。我们使用ReaChR光遗传激活了伤害性ASH感觉神经元，从而触发了逃避反应并增加了唤醒。此外，我们使用ArchT光遗传抑制了睡眠神经元RIS，已知这种疾病会损害睡眠。两种光遗传学操作均降低了存活率。因此，OptoGenBox提供了一种负担得起的系统，用于研究秀丽隐杆线虫甚至其他小动物的关键生物过程的光遗传学操纵的长期后果。