OMR-Arena: Automated Measurement and Stimulation System to Determine Mouse Visual Thresholds Based on Optomotor Responses

Abstract

Measurement of the optomotor response is a common way to determine thresholds of the visual system in animals. Particularly in mice, it is frequently used to characterize the visual performance of different genetically modified strains or to test the effect of various drugs on visual performance. Several methods have been developed to facilitate the presentation of stimuli using computer screens or projectors. Common methods are either based on the measurement of eye movement during optokinetic reflex behavior or rely on the measurement of head and/or body-movements during optomotor responses. Eye-movements can easily and objectively be quantified, but their measurement requires invasive fixation of the animals. Head movements can be observed in freely moving animals, but until now depended on the judgment of a human observer who reported the counted tracking movements of the animal during an experiment. In this study we present a novel measurement and stimulation system based on open source building plans and software. This system presents appropriate 360 stimuli while simultaneously video-tracking the animal's head-movements without fixation. The on-line determined head gaze is used to adjust the stimulus to the head position, as well as to automatically calculate visual acuity. Exemplary, we show that automatically measured visual response curves of mice match the results obtained by a human observer very well. The spatial acuity thresholds yielded by the automatic analysis are also consistent with the human observer approach and with published results. Hence, OMR-arena provides an affordable, convenient and objective way to measure mouse visual performance.

Requirement for Microglia for the Maintenance of Synaptic Function and Integrity in the Mature Retina

“…In addition, we performed in vivo assessments of optomotor responses to presentations of visual stimuli following 30 d of microglial depletion (Kretschmer et al, 2013). Under both scotopic and photopic conditions, the optomotor response curves demonstrated by microglial-depleted mice followed the same general profile as that demonstrated by nondepleted controls, with their responses being were slightly but nonsignificantly lower relative to controls (Fig.…”

“…These data are used to automatically readjust the presentation of the stimuli to changing head positions to keep the size of the gratings constant (the analysis software used, OmrArena, was modified from a version previously published; Kretschmer et al, 2013). OMR measurements were objectively obtained using an automated approach during off-line analysis and do not involve subjective grading or input from a human observer.…”

A system to measure the Optokinetic and Optomotor response in mice

“…The pattern is rotated around the animal at a constant velocity [1] in one [1, 5] or alternating directions [7]. Alternatively the velocity can be changed sinusoidally [8, 9].…”

Assessing nest-building behavior of mice using a 3D depth camera

“…Various devices to observe or record the behavior of rodents have been developed (e.g., Kretschmer et al, 2013;Publicover Q5 et al, 2009;Spink et al, 2001). However, most of the devices were designed to analyze behaviors in two dimensions (2D), while most animals behave in three dimensions (3D).…”