Visualizing Gravity Sensation

Vestibular sensation anchors our perception of the environment and is crucial for maintaining balance during locomotion. Vertebrate animals use the evolutionarily conserved vestibular system to sense linear and angular acceleration. However, tetrapods on land exhibit complex balance behaviors that are difficult to capture and quantify. Zebrafish (Danio rerio) is a tractable small vertebrate exhibiting innate balance behavior that is straightforward to measure under water. Larval zebrafish are inherently unstable due to their front-heavy body plane. Larval zebrafish rely on swimming to prevent nose-down rotation and maintain balance. To visualize balance behavior, we developed a scalable apparatus to measure posture and locomotion (SAMPL). SAMPL employs a simple marker-less pose estimation algorithm to extract posture and locomotion data and can be adapted for various small animals. Through a combination of high-throughput behavior assays, 2-photon laser ablation, and functional imaging techniques, we have identified the neuronal substrates underlying vestibular control of balance. These studies establish a foundation for comprehending the neural mechanisms of vestibular perturbations, compensation, and rehabilitation under pathological conditions.

Learning Objectives:

1. Explain how the vestibular system sense acceleration.

2. Understand a basic algorithm for pose estimation.

3. Describe vestibular contribution to locomotion in zebrafish.