Quantitative measurements of the optokinetic response in adult fish

Abstract

Small teleost fish are increasingly used for studying the genetic basis of vision. In particular, zebrafish (Danio rerio) and medaka (Oryzias latipes) are commonly used vertebrate model organisms in developmental research, including research on the development of visual function. A multitude of behavior-based visual tests are established for larvae that have been successfully used to identify and characterize visual defects in genetically manipulated strains of these species. Testing the visual system of adult fish has proven to be more difficult for a number of reasons, including complications in restraining fish, or shoaling and dominance behavior interfering with visual behavior in population screening assays. In this paper, we present a simple and cost-effective method to quantitatively measure the optokinetic response (OKR) of individual adult zebrafish and medaka, which can be used to characterize visual capabilities of adult fish. This method can be applied to any fish species of similar size.

Gucy2f zebrafish knockdown – a model for Gucy2d-related leber congenital amaurosis

“…Robust visually-guided assays, including the optomotor and optokinetic tests allow quantitative measurements of visual impairment in zebrafish. [17][18][19][20][21][22] Yan, Sun and Engelhardt stressed the advantage of non-mouse animal models for accelerated gene-targeting research. 23 Knockdown techniques, which are readily available in zebrafish, are particularly suited for research of early onset genetic blindness such as LCA and can be used to develop alternative LCA-models.…”

Analysis of Optokinetic Response in Zebrafish by Computer-Based Eye Tracking

“…In our laboratory, different processing methods have been applied in the past depending on the research question ( 11,13,16,17 ) . Here, we describe in detail the method of choice for a rapid screening of vision defects.…”

“…Using linear projection, only monocular stimulation is possible ( 11 ) . When the projector is placed below the subject, the gratings are projected via a mirror to the whole drum enabling binocular stimulation ( 12,13 ) . In order to avoid visible light from the projector in fl uencing the recording, the animal is illuminated from below with infrared-emitting diodes.…”

“…OKR testing in adult fi shes is more challenging, mainly because of the dif fi culty of restraining body movements of the fi sh. We were able to solve this problem and published a working method for OKR measurement in the adult ( 13 ) . In the same year, an alternative setup has been described by Zou et al ( 15 ) .…”

“…We then describe our standard eye movement quanti fi cation approach which allows for detection of subjects with vision defects as well as for investigation of the OKR behavior itself. Since our system is under continuous development ( 1,2,11,13,16,17 ) , some of the details described in the protocol may change over time. However, our detailed protocol should enable the reader to apply the methodology of quantitative OKR measurements.…”