Behavioral evaluation of visual function of rats using a visual discrimination apparatus

Abstract

A visual discrimination apparatus was developed to evaluate the visual sensitivity of normal pigmented rats (n = 13) and S334ter-line-3 retinal degenerate (RD) rats (n = 15). The apparatus is a modified Y maze consisting of two chambers leading to the rats' home cage. Rats were trained to find a one-way exit door leading into their home cage, based on distinguishing between two different visual alternatives (either a dark background or black and white stripes at varying luminance levels) which were randomly displayed on the back of each chamber. Within 2 weeks of training, all rats were able to distinguish between these two visual patterns. The discrimination threshold of normal pigmented rats was a luminance level of −5.37 ± 0.05 log cd/m 2 ; whereas the threshold level of 100-day-old RD rats was −1.14 ± 0.09 log cd/m 2 with considerable variability in performance. When tested at a later age (about 150 days), the threshold level of RD rats was significantly increased (−0.82 ± 0.09 log cd/m 2 , p < 0.03, paired t-test). This apparatus could be useful to train rats at a very early age to distinguish between two different visual stimuli and may be effective for visual functional evaluations following therapeutic interventions.

Strain-dependent effects on acquisition and reversal of visual and spatial tasks in a rat touchscreen battery of cognition

“…In fact, the touchscreen approach is frequently criticized for requiring rodents to use vision which is not thought to be their preferred modality for exploring their environment. This problem may be aggravated in albino strains that are well known to have poor vision relative to many pigmented rat strains [22,33,36]. However, a sole study in the rat has reported that an albino rat strain (Sprague Dawley) was able to acquire a simple visual discrimination with complex stimuli as efficiently as a pigmented strain (Lister-Hooded rat).…”

Changes in Retinal Morphology, Electroretinogram and Visual Behavior after Transient Global Ischemia in Adult Rats

“…One apparatus consisted of several compartments including a curved tube, one introduction chamber, two escape alleys, three swing doors and one home cage. This apparatus was designed to train rats to distinguish two different visual stimuli [12]. The other apparatus was the black-white box which is formed by two chambers (the white and black chamber) with a door opening between them.…”

Divergence of dim-light vision among bats (order: Chiroptera) as estimated by molecular and electrophysiological methods

“…Furthermore, over the electroretinograms (ERGs), which only detect retinal photoreceptor capacity40, the f-VEP has advantages in detecting visual ability. The absolute visual thresholds (log cd/m 2 •s) of Pteropodidae (−6.30 and −6.37), that were even lower than those of rats (−4.99 for pigmented rats and −5.37 cd/m 2 •s for albino rats3241), were lowest, following the Emballonuridae (−3.71) and insectivorous bats (−1.90). The results implied that Pteropodidae and Emballonuridae possessed better visual capacity than the insectivorous bat.…”