Evaluation of visual function in Royal College of Surgeon rats using a depth perception visual cliff test

Abstract

Preserving of vision is the main goal in vision research. The presented research evaluates the preservation of visual function in Royal College of Surgeon (RCS) rats using a depth perception test. Rats were placed on a stage with one side containing an illusory steep drop (“cliff”) and another side with a minimal drop (“table”). Latency of stage dismounting and the percentage of rats that set their first foot on the “cliff” side were determined. Nondystrophic Long–Evans (LE) rats were tested as control. Electroretinogram and histology analysis were used to determine retinal function and structure. Four-week-old RCS rats presented a significantly shorter mean latency to dismount the stage compared with 6-week-old rats (mean ± standard error, 13.7 ± 1.68 vs. 20.85 ± 6.5 s, P = 0.018). Longer latencies were recorded as rats aged, reaching 45.72 s in 15-week-old rats (P < 0.00001 compared with 4-week-old rats). All rats at the age of 4 weeks placed their first foot on the table side. By contrast, at the age of 8 weeks, 28.6% rats dismounted on the cliff side and at the age of 10 and 15 weeks, rats randomly dismounted the stage to either table or cliff side. LE rats dismounted the stage faster than 4-week-old RCS rats, but the difference was not statistically significant (7 ± 1.58 s, P = 0.057) and all LE rats dismounted on the table side. The latency to dismount the stage in RCS rats correlated with maximal electroretinogram b-wave under dark and light adaptation (Spearman’s rho test = −0.603 and −0.534, respectively, all P < 0.0001), outer nuclear layer thickness (Spearman’s rho test = −0.764, P = 0.002), and number of S- and M-cones (Spearman’s rho test = −0.763 [P = 0.002], and −0.733 [P = 0.004], respectively). The cliff avoidance test is an objective, quick, and readily available method for the determination of RCS rats’ visual function.

Visual Behavior Impairments as an Aberrant Sensory Processing in the Mouse Model of Fragile X Syndrome

“…We can hypothesize that this phenotype penetrance is linked to the retino-geniculo-cortical pathway state in absence of FMRP. Indeed, it has been clearly demonstrated that modification of this pathway by targeting the retina or the visual brain areas modulate depth perception (Mazziotti et al, 2017; Tzameret et al, 2019). From a molecular standpoint, the decreased efficiency of the retino-geniculo-cortical pathway in Fmr1 −/y mice must be linked to the impairments of neuron-specific functions such as glutamate/GABA pathways or synaptic transmissions (Davidovic et al, 2011; Doll et al, 2017) due to well described protein deregulation in FXS conditions, such as PSD95, mGlur5, or SNARE complex expression defects (Zhu et al, 2011; Westmark, 2013; Tang et al, 2015; Aloisi et al, 2017).…”

Effect of Applying Binocular Visual Training after Slanted Lateral Rectus Recession on Orthophoric Rate and Binocular Visual Function Recovery on Patients with Convergence Insufficiency-Type Intermittent Exotropia

“…After surgery, children in group B accepted the conventional visual function rehabilitation training, a new pair of glasses was prescribed for each child by a professional optometrist for refraction correction, the routine quantitative cover was carried out, and by combining the family therapy with clinical treatment, an individualized diagnosis and treatment plan was made by the physician for the children to visit our clinic and finish corresponding tests and training. e specified fine training tasks including threading a needle, delineating practice, and stringing small beads were finished at home, the children revisited the clinic regularly, and their files were recorded [9,10].…”

Effect of recurrent severe insulin-induced hypoglycemia on the cognitive function and brain oxidative status in the rats

“…Additionally, for a comprehensive evaluation of the neurological clinical symptoms associated with damage to different brain regions due to repeated severe hypoglycemic episodes, more extensive clinical assessments are necessary. In this study, initial assessments of visual acuity in rats were carried out using the optokinetic response test [ 40 , 41 ] and the visual cliff test [ 42 , 43 ].…”