RotaRod Test in Rodent Models of Stroke

At a glance

What Is the RotaRod Test?

The baton rotarod test is one of the most widely used tests for assessing motor function and balance in rats and mice. The test was initially used to study neurological function and later used by many to study brain injuries such as stroke. The rotarod device is a rod that rotates at an adjustable speed. The speed of the rod increases over time and the amount of time the animal remains on the device is recorded.

Fig. 1 A Rotarod with beams to detect dropped animals (TSE systems). (Balkaya, et al., 2010)

Related Services

As a leading stroke research provider, Ace Therapeutics offers the rotarod test to assess locomotor function in rat and mouse models of focal ischemic stroke. This test allows us to help our clients examine balance behavior and motor function in the acute and chronic phases after stroke, and to identify patterns of recovery and evaluate the neuroprotective effects of new therapies.

Specific Procedures for the RotaRod Test

The setup for the rotarod test consists of a rod measuring 3 cm in diameter and 40 cm in length, with its surface covered in sticking plasters to enhance roughness. The rod is rotated by an electric motor at a speed of 20 rpm. To ensure the safety of the animals, a landing platform with a soft surface is positioned 18 cm below the rod to cushion their falls.

Training Phase

Before testing, animals undergo training to familiarize themselves with the task. Preoperative training is particularly important in long-term, repetitive post-stroke testing to distinguish true recovery from motor learning. It also helps eliminate the influence of motivational factors on test results.

Animals are first placed on the stationary rod for 30 seconds. The rod is then set to rotate at a slow, constant speed of 4 rpm. Training continues until the animals can remain on the rotating rod for at least 1 minute. During training, if an animal falls before the trial ends, it should be promptly placed back on the rod to complete the session. Additionally, animals should only be returned to their home cage after finishing the trial to enhance their motivation to remain on the rod.

Testing Phase

After completing the training phase, animals are subjected to the testing trial. In this trial, the rod begins rotating at 4 rpm and gradually accelerates to 20 rpm over a span of 2 minutes. The latency before they fall on the platform is recorded as a measure of their motor coordination and balance. Each trial is repeated 3-5 times for each mouse or rat, and the average latency to fall is calculated as the final score. To ensure accurate results, sufficient inter-trial intervals must be provided, allowing the animal to recover fully from any fatigue induced by the testing process.

Advantages and Disadvantages of the RotaRod Test

Advantages	Disadvantages
It provides precise and reproducible measurements of motor coordination, balance, and endurance. It is frequently used to detect subtle motor impairments that might not be apparent through observational methods. Its versatility allows for the adjustment of test parameters, such as rod speed and acceleration rates, to suit specific experimental objectives or the severity of impairments being studied.	Specialized equipment is required, which may not be readily available in all laboratories. Animals must undergo proper habituation and training to ensure reliable and consistent results. Variability in training protocols across studies can also impact comparability, emphasizing the need for standardized procedures. Factors such as motivation, fatigue, and stress can influence performance, highlighting the importance of controlling these variables in experimental design.

Advantages

Disadvantages

It provides precise and reproducible measurements of motor coordination, balance, and endurance.
It is frequently used to detect subtle motor impairments that might not be apparent through observational methods.
Its versatility allows for the adjustment of test parameters, such as rod speed and acceleration rates, to suit specific experimental objectives or the severity of impairments being studied.

Specialized equipment is required, which may not be readily available in all laboratories.
Animals must undergo proper habituation and training to ensure reliable and consistent results.
Variability in training protocols across studies can also impact comparability, emphasizing the need for standardized procedures.
Factors such as motivation, fatigue, and stress can influence performance, highlighting the importance of controlling these variables in experimental design.

Reference

Balkaya, M., & Endres, M. (2010). Behavioral testing in mouse models of stroke. Rodent models of stroke, 179-197.