Virtual Booth

Visual function tests used in rodents include direct visual tests (optokinetic response test) and trained visual-behaviour tests(two-direction water maze test). These tests are commonly used to assess visual ability and utilized in retinal neurodegeneration studies in rodents. In this innovation, we demonstrated the use of open field mirror test as an alternative tool in comparing rats with visual impairment to rats with normal vision. The dimension of the open field arena was 82 cm x 82 cm. The arena was then divided into 3 rectangular zones with similar length and width (27.33 cmx 27.33 cm) labelled A, B, and C. A mirror with dimensions of 25 x 25 cm was placed in the middle of the wall in zone A. A reversed mirror of the same size with a non-reflective surface was placed on the opposite wall in Zone C, the surface of which mimicked the actual mirror except that it was not a reflective surface. Zone B contained no mirror and was designated as a ‘null zone’. For the open field test, the experimental sessions were recorded with a digital video camera. Prior to the test, rats were acclimatised with the arena. During the actual test, each rat was placed in the central part of the open field arena. The open field arena was cleaned with 70% alcohol at the start and in between test sessions to remove all sensory stimuli. The following behavioural parameters were observed for 10 minutes: i) total distance travelled; (ii) frequency of freezing episodes (frequency at which the animal does not move for more than 2 seconds); (iii) frequency of rearing episodes (frequency at which the animal stood on its hind limbs) ;(iv) frequency of grooming episodes (frequency of licking and scratching) ;(v) number of faecal pellets excreted (vi) frequency of zone crossings. The data was then analysed using Any Maze software version 4.0. Therefore, in conclusion, open field mirror test could contribute as an alternative tool to estimate the visual function deterioration in rats.