Sensory pathways are typically studied by starting at receptor neurons and following postsynaptic neurons into the brain. However, this leads to a bias in analyses of activity toward the earliest layers of processing. Here, we present new methods for volumetric neural imaging with precise across-brain registration to characterize auditory activity throughout the entire central brain of Drosophila and make comparisons across trials, individuals and sexes. We discover that auditory activity is present in most central brain regions and in neurons responsive to other modalities. Auditory responses are temporally diverse, but the majority of activity is tuned to courtship song features. Auditory responses are stereotyped across trials and animals in early mechanosensory regions, becoming more variable at higher layers of the putative pathway, and this variability is largely independent of ongoing movements. This study highlights the power of using an unbiased, brain-wide approach for mapping the functional organization of sensory activity.

通常通过从受体神经元开始并跟随突触后神经元进入大脑来研究感觉通路。然而，这会导致对活动分析的偏向于最早的处理层。在这里，我们提出了体积神经成像的新方法，具有精确的跨脑配准，以表征整个果蝇中央大脑的听觉活动并在试验、个人和性别之间进行比较。我们发现听觉活动存在于大多数大脑中枢区域和对其他方式有反应的神经元中。听觉反应在时间上是多样的，但大多数活动都与求爱歌曲的特征有关。在早期机械感觉区域的试验和动物中，听觉反应是刻板的，在假定通路的更高层变得更加可变，并且这种可变性在很大程度上独立于正在进行的运动。这项研究强调了使用无偏见的全脑方法来绘制感觉活动的功能组织图的力量。