When examining mice for research purposes, it becomes necessary to evaluate their behavior since mice are unable to participate in surveys or communicate verbally. Consequently, researchers must explore alternative methods to gauge alterations in their behavior. A common approach to accomplish this is by employing a rotarod.

What Is A Rotarod?

Consider a treadmill designed specifically for mice; this is how many scientists perceive the rotarod apparatus. This instrument serves as a means to evaluate various aspects of motor function in mice, including rodent motor coordination, motor function, motor deficits, balance, motor learning, and performance in mice.

Moreover, it allows for the assessment of gait, coordination, and muscle strength in these rodents. The rotarod test has proven to be an effective method used to assess motor coordination and balance in rodents.

The mouse is positioned on a horizontal rod that rotates. Initially, the rod operates at a specific speed, and throughout the test, the rotation speed gradually increases for a set duration.

The mice’s ability to stay on the accelerating rod is observed by researchers. Both the duration of their stay and the initial speed of rod acceleration are examined. A rotarod allows simultaneous monitoring of multiple mice, with vertical barriers ensuring their separation on the rotating rod.

Scientists commonly employ this test in rodent research. The apparatus ensures the mice experience no pain or distress. The natural instinct of the animals to remain on the rod is leveraged, but even if they fall, no harm will come to them.

The rotarod test is often likened to a hamster or gerbil running on an exercise wheel. However, the crucial distinction lies in the mechanical propulsion of the rotarod, as opposed to the mice providing the power themselves.

The rotarod test was initially developed by N.W. Dunham and T.S. Miya. Early versions had fixed speed, but modern models feature constant or escalating speeds. Researchers discovered that fixed speeds had limited value, as mice often fell off the rod due to coordination issues initially. When mice managed to stay on a rod rotating at a fixed speed, their endurance was tested rather than their coordination.

Keep in mind that body weight might influence performance in this test. Thus, consideration of body weight is essential for better evaluation of the data.

The Benefits Of Using Rotarods

The rotarod is employed by scientists in measuring motor coordination of mice, enabling comparison between different mouse models. For instance, they can initially evaluate mice with a specific medical condition, followed by administering medication and conducting subsequent tests. By recording any variations, scientists can determine the efficacy of the medication.

The utilization of the rotarod provides scientists with a quantifiable continuous variable that can be discretely measured. By analyzing the collected data, scientists can quantify the outcomes of various procedures, conditions, and drugs. This objective approach eliminates the need for subjective assessments of animal behavior, such as mice, resulting in nearly perfect inter-rater reliability.

To achieve inter-laboratory reliability, scientists must replicate all parameters, including the size of the cylinder, the constant rotational speed, and the extent of training or practice given to the mice before testing. This ensures consistency across different research facilities.

Applications of Rotarods in Testing

Scientists employ rotarods in various testing scenarios. For example, when evaluating new prescription medications, researchers often examine motor behavior impairments in mice. Their aim is to identify medications that may cause subtle alterations in behavior.

While such impairments might remain unnoticed in humans for a prolonged duration, they become more evident in mice. By conducting these tests, researchers can identify drugs that may raise concerns when administered to the human population. Additionally, this testing method has shed light on trauma resulting from brain injuries. Furthermore, studies have demonstrated that alcohol negatively affects motor performance in the rotarod test in mice.

Scientists can gain insights into the neural components responsible for the effects of various chemical agonists and antagonists by administering them to mice. The use of rotarods has proven valuable in enhancing our understanding of human behavior.

To elucidate the genes regulating mammalian balance and coordination, researchers conducted rotarod tests on genetically knockout animals. They examined the performance of animals with specific brain lesions across various animal models. Through these experiments, researchers could identify the brain structures essential for maintaining balance in mammals.

Omnitech Rotarods

When researchers seek to acquire rotarods, Omnitech is a popular choice. Featuring their Accurator Four Animal Rotarod.

The AccuRotor Four Animal Rotarod

The AccuRotor Four Animal Rotarod assesses rodent coordination and can be paired with Fusion software for customizable trial setups. Featuring a precision-controlled servo motor, this device rotates a suspended cylinder that enhances rodent grip. Mice or rats maintain balance on the rod during testing.

In case a rodent falls off the rod, the software promptly records the duration of their stay or the intervals between falls in experiments involving controlled durations. The enclosed chamber design beneath each rod prevents subjects from escaping or triggering false alarms in adjacent lanes. Each chamber is equipped with a status indicator, a start button, sensors to detect mouse falls, additional motor skill learning tests, and a waste collection tray for the subject.

Researchers have the option to utilize the device with both mice and rats, with available models in standard and tall versions. For added convenience, researchers may choose to upgrade to a stand-alone unit featuring a digital readout display. Setting up experiments using Fusion software is a seamless process, allowing users to program the desired number of trials for each subject and adjust animal batch sizes with ease.

They also have the flexibility to enable individual trial re-runs as necessary and utilize the acceleration profile editor to create custom acceleration profiles. With this software, large groups can be tested, and multiple trials can be conducted for individual animals, providing extensive testing capabilities.

Final Thoughts

Rotarods offer considerable advantages for a wide range of experiments, proving particularly valuable in testing rodents across diverse conditions. It is advisable to explore the complete range of Omnitech products to identify the most suitable ones for the specific experiment at hand. Contact Omnitech today to learn more.