Benefits of Touchscreen Testing
Testing of novel therapeutics for neurological diseases is dependent on valid animal models expressing elements of pathological and/or behavioral changes detected in human patients. For example, in animal models of neurodegenerative disease (Alzheimer’s disease and Parkinson’s disease), a key clinical endpoint is cognitive improvement that should be evaluated in a preclinical study. However, cognitive changes are challenging to measure in animal models as typically, animal model behavior does not directly translate to human conditions. The majority of conventional behavioral tests done on animal models of disease include water maze or fear conditioning testing where the animal is required to find a hidden or visible platform in a pool of water. This type of experimental setting does not compared directly to human assessment so it is difficult to translate results from water maze like tests to the clinic.
Touchscreen testing in small animals - similar to CANTAB testing in humans to measure cognitive decline.
This video shows how touchscreen testing is used to identify cognitive changes and flexibility in neurodegeneration and apathetic responses in depression studies.
Charles River offers an alternative method to measure mouse behavior analysis via touchscreen-based testing. This method is a translatable approach to performing cognitive neuroscience tests. The touchscreen testing study design typically includes a training period prior to gathering data from a cohort. The data is quantified to generate actionable data on the efficacy of a therapy to halt or reverse cognitive decline.
The touchscreen tests possess several advantages over traditional methods of rodent cognitive assessment.
- The method is highly translational as it relies on the stimuli (images and locations on a computer screen) and actions (screen touches) similar to those used in human cognitive assessments, e.g., the Cambridge Neuropsychological Test Automated Battery (CANTAB).
- These tests can measure multiple neuropsychological endpoints including cognitive decline, cognitive flexibility, vigilance and response inhibition.
- Touchscreen tests have positive appetite motivation and minimal motor demands and more importantly, animals are never excessively stressed or punished, but instead receive food rewards for correct responses.
- Due to their emphasis on sustained performance, touchscreen tests can be used in longitudinal pharmacological studies.
- Non-invasive touchscreen assessments allow for the simultaneous or subsequent use of animals in other behavioral or functional experiments (e.g., MRI), which facilitates comparison and compilation of outputs from multiple experimental types.
Touch Screen Testing Frequently Asked Questions (FAQs)
How did touchscreen testing evolve as a method?
About 30 years ago, scientists developed CANTAB, or the Cambridge Neuropsychological Test Automated Battery to detect cognitive impairments in individuals with Alzheimer’s disease and Parkinson’s disease. This battery is now an important tool in many clinical trials.This idea was extended first to large animal models and then rodents as a measurement of cognitive decline. Touchscreen testing in rodents was developed in the mid-1990s as a useful tool to perform cognitive neuroscience testing. Though this technique was developed from human to mouse, a recent study described an object-location associative task developed for small animals being used in humans - an example of reverse translation.
What are the major benefits of touchscreen testing compared to traditional methods like water maze?
One of the principal benefits of touchscreen-based tasks in mice is their greater similarity to the setting in which human subjects are tested - nosepoke reactions to images on the screen are more translational than swimming to find a platform. Additionally, swimming can be too strenuous for specific animal models that have movement disorders. A food reward will elicit a more true learning response compared to learning based on the desire to escape the unpleasant watermaze. Touchscreen tasks are automated and more amenable for fine tuning than watermaze testing.
How would you design a touchscreen study to test a new drug candidate for Alzheimer’s disease?
Select an appropriate mouse model - either a beta amyloid or tau based mouse model. Then, identify the key questions: which neuropsychological domain are we going to target with this drug? Is this learning and memory, attention or, perhaps, motivation? This will help identify the battery of cognitive tests to use. It would also be a good idea to identify which CANTAB tasks have reported a deficit in Alzheimer’s disease patients and whether those CANTAB tasks have analogous mouse versions.