Behavioral assessment of visual acuity in mice and rats

Abstract

We have developed a simple computer-based discrimination task that enables the quick determination of visual acuities in rodents. A grating is displayed randomly on one of two monitors at the wide end of a trapezoidal-shaped tank containing shallow water. Animals are trained to swim toward the screens, and at a fixed distance, choose the screen displaying the grating and escape to a submerged platform hidden below it. Both mice and rats learn the task quickly. Performance falls below 70% when the spatial frequency is increased beyond 0.5 cycles in most C57BU6 mice, and around 1.0 cycles per degree (cpd) in Long-Evans rats.

Acceleration of Visual System Development by Environmental Enrichment

“…Behavioral assessment of visual acuity started at P19; EC (n ϭ 7), untreated SC (n ϭ 10), and DMSO-or rolipram-treated SC WT mice (n ϭ 16) were trained and tested every 3 d in the visual water task (Prusky et al, 2000b) to assess their visual acuity. Visual water task trains animals to first distinguish a low (0.05 cycles/ degree) spatial frequency vertical grating from gray and then tests the limit of this ability at increasing spatial frequencies.…”

Variation in visual acuity within pigmented, and between pigmented and albino rat strains

“…Our lab [18] and others [7,13,22,23] have reported that the adult grating acuity of normal Long-Evans strain rats is around 1.0 cycle/degree (c/d). We have also reported that visual deprivation in rats during a physiologically-defined critical period early in life [26] results in significantly reduced visual acuity [19].…”

“…Visual acuity was assessed psychophysically using the Visual Water Task [18]: a two-alternative, forced-choice visual discrimination task in which the threshold of animals to discriminate a sine wave grating from gray of the same mean luminance was assessed.…”

“…The scale of the albino acuity deficit can be further illustrated by the facts that there was no overlap in individual acuity measurements of albino and pigmented animals, and the acuity of albino rats is effectively the same as that of a mouse [18], an animal with substantially smaller eyes.…”

Visual thalamocortical circuits in parvalbumin-deficient mice

“…Specific parvalbumin immunoreactivity (PV-ir) was identified within subpopulations of ganglion and amacrine cells of the mouse retina (Endo et al, 1986;Sanna et al, 1993;Kim and Jeon, 2006). However, the study of the functional properties of the visual pathway of mice has attracted limited attention by the neurophysiologists in the past probably because of the poor visual acuity of this species (Prusky et al, 2000). In mice, less than 3% of the entire retinofugal pathway projects ipsilaterally (Dräger and Olsen, 1980), and the number of retinal ganglion cells viewing a point in binocular space is 9 times smaller for the ipsilateral than for the contralateral retina (Dräger and Olsen, 1980).…”