A rotometer is a powerful activity system designed to measure rotational behavior and movements in lab animals such as rodents. The study of drug-induced circling behavior in animals is key for drug development. For example, understanding rotational movements aids in demystifying the exact root causes of neurodegenerative diseases such as Parkinson’s disease and helps devise effective treatment.
How does the rotometer work?
A rotometer consists of a transparent test enclosure, typically 30-45 cm large, with sloped bases where the animals are loaded. The animals are held in the enclosure on the station by placing flexible harnesses around their body. The harness mounts are long and specially designed to facilitate the turning of the loaded animal within its length, i.e., an in-place rotation, and ensure that it stays in the center of the enclosure. This design requirement is crucial for recording true rotations and distinguishing exploratory behavior from drug-induced rotations. A rotometer can record both clockwise and anti-clockwise rotations.
The rotometer system is run via a control unit that can be easily connected to a computer through USB. The control unit continuously monitors and displays elapsed runtime sessions and ongoing activity counts for each enclosure during testing.
The rotometer stores all the study results in a database in a single file (table) format that can be readily exported. The user, therefore, does not have to manually move around the data from multiple files to analyze it through statistical software.
Rotometer test stations offer greater flexibility by allowing the configuration of multiple rotometers independently using a single computer system. Such test stations are highly useful and productive for the rapid testing of large subject groups. Moreover, each rotometer could have an independent start/stop switch. A typical rotometer offers full-turn and quarter-turn options to count partial rotations. The diagnostic function displays the status of individual enclosures and enables their testing.
Key Applications
The key applications of the rotometer include motor assessment tests and facilitating scientific research in the field of progressive nervous system disorders such as Parkinson’s disease and traumatic brain injury (TBI), acquired brain injury, and spinal cord injury. All these disorders directly impact the movement of a patient. Animals, typically rodents, are used to mimic the human condition or pathology in laboratory experiments. Animals display rotational behavior for several reasons, including uneven levels of neurotransmitters (e.g., dopamine) in the brain due to physical lesions or tumors, anxiety, stress, exposure to or withdrawal from drugs, or developmental anomalies.
Analysis of rotational movement is a popular scientific technique to elucidate the behavioral effects of various drugs and lesions on brains. Such rotational tests based on rotometers are commonly used in experiments that utilize animal models of Parkinson’s disease. For example, dopamine replacement therapy is the commonly used treatment for Parkinson’s disease. But over time, motor complications such as abnormal involuntary movements that interfere with normal physiological motor activities arise in patients due to dopamine therapy. Therefore, an in-depth analysis of the effect of drugs on the rotational movements is highly critical for devising effective treatment and therapies for motor symptoms of nervous system disorders.
To evaluate the efficacy of the lesions, the animals are induced with different drugs, and a rotometer is used to measure the drug-induced rotations and their impact on motor activity. Since rotometers can measure clockwise and anti-clockwise rotations, they are also used to identify asymmetric motor activities, i.e., why and how the brain’s lesioned side behaves differently from the intact one. Such analysis allows for the identification of how different drugs affect motor activities and helps categorize these animals into different treatment groups based on their average rotations.
If you would like to know more about the rotometer activity systems offered by San Diego Instruments, get in touch with us today.
References:
- Valastro et al., Proteomic analysis of striatal proteins in the rat model of L-DOPA-induced dyskinesia, Journal of Neurochemistry, 2007;102;1395–1409.
- Duty et al., Animal models of Parkinson’s disease: a source of novel treatments and clues to the cause of the disease. British Journal of Pharmacology 2011;164(4):1357-1391.
- https://www.ugobasile.com/products/catalogue/motory-coordination-grip-strength-activity/item/24-43000-rotometer
- https://sandiegoinstruments.com/wp-content/uploads/2018/08/Rotometer-DataSheet-optimized.pdf