Rotorod. The rotorod test is a test which involves rats walking on a rotating drum. This test is widely used to assess coordination or ataxia in animals. Performance is measured by the duration the animal stays on the drum as a function of drum speed. Durham Miya, in 1957, first described the roto-rod to evaluate strength and coordination in animals. The neurological deficits indicated by this test include ataxia, sedation and hyperexcitability. Training consists of placing the rat on a drum rotating at 6 revolutions per minute. As soon as the rat falls off the roto-rod it is immediately placed back on the drum. Training sessions terminate when the rat remains on the rod continuously for 2 min or up to 20 trials, whichever is earlier. On the second day, the cumulative time spent on the roto-rod by each rat (control and treated) is recorded with a cut off of 2-5 min.
The Roto-rod treadmills in the RNL are made by Med Associates (ENV-575) and rotate at 4.0 to 40 RPMs. The Shaft Diameter is 2.75”, Lane Width is 3.5”, Fall Height is 10.5” and the Lane Divider diameter is 15.64”.
Locomotor Activity. Locomotor activity is measured in an open field over a period of 30 to 120 min. Infrared beam breaks automatically record movement in the open field. Activity of non-treated rats typically declines over the first 30 min.
The eight Locomotor Chambers in the RNL were manufactured by Kinder-Scientific and measure 16 x 16” square with wall height of 15”. Beam heights are at 1 and 4” and can measure both locomotion and rearing.