School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Curr Biol. 2018 Dec 3;28(23):3711-3722.e3. doi: 10.1016/j.cub.2018.09.060. Epub 2018 Nov 15.
The vestibular system, which reports on motion and gravity, is essential to postural control, balance, and egocentric representations of movement and space. The motion needed to stimulate the vestibular system complicates studying its circuitry, so we previously developed a method for fictive vestibular stimulation in zebrafish, using optical trapping to apply physical forces to the otoliths. Here, we combine this approach with whole-brain calcium imaging at cellular resolution, delivering a comprehensive map of the brain regions and cellular responses involved in basic vestibular processing. We find responses broadly distributed across the brain, with unique profiles of cellular responses and topography in each region. The most widespread and abundant responses involve excitation that is graded to the stimulus strength. Other responses, localized to the telencephalon and habenulae, show excitation that is only weakly correlated to stimulus strength and that is sensitive to weak stimuli. Finally, numerous brain regions contain neurons that are inhibited by vestibular stimuli, and these neurons are often tightly localized spatially within their regions. By exerting separate control over the left and right otoliths, we explore the laterality of brain-wide vestibular processing, distinguishing between neurons with unilateral and bilateral vestibular sensitivity and revealing patterns whereby conflicting signals from the ears mutually cancel. Our results confirm previously identified vestibular responses in specific regions of the larval zebrafish brain while revealing a broader and more extensive network of vestibular responsive neurons than has previously been described. This provides a departure point for more targeted studies of the underlying functional circuits.
前庭系统负责报告运动和重力信息，对于姿势控制、平衡和自我中心的运动和空间感知至关重要。刺激前庭系统所需的运动使得研究其回路变得复杂，因此我们之前开发了一种在斑马鱼中进行虚构性前庭刺激的方法，使用光阱将物理力施加到耳石上。在这里，我们将这种方法与全脑钙成像相结合，以细胞分辨率提供涉及基本前庭处理的大脑区域和细胞反应的综合图谱。我们发现反应广泛分布在大脑中，每个区域都有独特的细胞反应和拓扑结构。分布最广泛和最丰富的反应涉及到与刺激强度成比例的兴奋。其他局限于端脑和缰核的反应表现出与刺激强度相关性较弱的兴奋，并且对弱刺激敏感。最后，许多脑区包含被前庭刺激抑制的神经元，这些神经元在其区域内的空间上通常是紧密定位的。通过对左、右耳石施加单独的控制，我们探索了全脑前庭处理的偏侧性，区分了具有单侧和双侧前庭敏感性的神经元，并揭示了来自耳朵的相互冲突的信号相互抵消的模式。我们的结果证实了在幼鱼斑马鱼大脑的特定区域中已经确定的前庭反应，同时揭示了比以前描述的更广泛和更广泛的前庭反应神经元网络。这为潜在功能回路的更有针对性的研究提供了一个起点。
