Magnetic eye tracking in mice.

Hannah L Payne,Jennifer L Raymond

doi:10.7554/elife.29222

Abstract

Eye movements provide insights about a wide range of brain functions, from sensorimotor integration to cognition; hence, the measurement of eye movements is an important tool in neuroscience research. We describe a method, based on magnetic sensing, for measuring eye movements in head-fixed and freely moving mice. A small magnet was surgically implanted on the eye, and changes in the magnet angle as the eye rotated were detected by a magnetic field sensor. Systematic testing demonstrated high resolution measurements of eye position of <0.1°. Magnetic eye tracking offers several advantages over the well-established eye coil and video-oculography methods. Most notably, it provides the first method for reliable, high-resolution measurement of eye movements in freely moving mice, revealing increased eye movements and altered binocular coordination compared to head-fixed mice. Overall, magnetic eye tracking provides a lightweight, inexpensive, easily implemented, and high-resolution method suitable for a wide range of applications.

Highlights

Many behaviors, from navigation and predation to avoidance of danger and pursuit of mates, are guided by vision (Chapillon, 1999; Coen and Murthy, 2016; Mather and Baker, 1980; Olberg et al, 2000; Yilmaz and Meister, 2013)
We developed a system for measuring eye movements in mice using magnetic sensing technology
The performance of the magnetic eye tracking system was first tested outside the mouse, where the position of the magnet and sensor could be precisely controlled, allowing systematic comparison of different magnet-sensor alignments

Summary

Introduction

From navigation and predation to avoidance of danger and pursuit of mates, are guided by vision (Chapillon, 1999; Coen and Murthy, 2016; Mather and Baker, 1980; Olberg et al, 2000; Yilmaz and Meister, 2013). Vision is actively controlled by eye movements, which localize and stabilize images on the retina. Eye movements are often measured in studies of visually guided behaviors, both for documentation and control of the visual inputs impinging on the retina, and as a behavioral output. The analysis of eye movements can provide a window on a variety of sensory, motor, and cognitive functions, such as attention, learning and memory, and decision-making (Duhamel et al, 1992; Kustov and Robinson, 1996; Raposo et al, 2012; Raymond and Lisberger, 1996). The measurement of eye movements can advance our understanding of the sophisticated neural processes underlying a wide range of functions in healthy and diseased brains

Methods

Results

Conclusion