Improving medical tests

Neurocognitive disorders such as schizophrenia and Alzheimer's disease are complex, and developing effective treatments for them is equally complex. In order to understand such diseases better, and to develop new therapies, researchers have been breaking down the disorders into their component characteristics and studying each of those characteristics individually.

A major strand of this approach involves improving the animal cognition tests used in research and drug discovery. The laboratory of Dr Tim Bussey and Dr Lisa Saksida in the Department of Experimental Psychology has been developing tests that will hopefully lead to better experiments on animal models of disease, and ultimately aid in the development of new drugs to treat neurocognitive disorders.

Drs Bussey and Saksida have designed a device that allows for improved ways of evaluating attributes associated with neurocognitive disorders. The device, a chamber which houses a computer-controlled testing environment, allows researchers to test memory, attention and problem-solving ability in a fully automated environment. Additionally, the tests are reward-based, which often give better results than those obtained through aversive testing.

In the Bussey-Saksida chamber a mouse uses a touchscreen interface identical to that used by humans. It uses high-contrast images, tailored to a mouse’s eyesight. Instead of pressing a lever or poking its nose into a hole, as is the case with many other mouse cognition tests, the mouse touches a screen with its nose in order to receive a food reward. This is very similar to the way in which cognition tests are administered in humans. A variety of tests can be administered using this method to form a cognitive profile of an animal. One application of this method is to understand how specific disease-related genes contribute to cognition.

Cambridge Enterprise licensed the Bussey-Saksida chamber to Leicester-based Campden Instruments in 2008, and a series of new medical tests to the company in 2009. Campden worked with the inventors and the Life Sciences team at Cambridge Enterprise to refine the chamber before launching it as a commercial product.

The main issue to be addressed was the sensitivity of the touchscreen. Most touchscreens are mass manufactured for human use, and are not sensitive enough for use with rodents. The Bussey-Saksida lab worked with Campden’s engineers to build the requisite sensitivity into the screen, and brought in additional enhancements from their collaborations with other cognitive neuroscientists in the field. The next issue for Campden was the resolution and clarity of the images used in the tests.

‘All of this comes down to establishing a standard which defines all the key technical points of the equipment,’ says Campden’s Managing Director. ‘If you want well-calibrated science, you need well-calibrated equipment.’ Once the enhancements to the Bussey-Saksida chamber were complete, Campden went through a beta testing phase with the Bussey-Saksida lab and other labs local to Cambridge before the commercial launch.

The next steps for the tests are to modify them for early stage human testing, as well as creating new animal tests to measure other aspects of cognitive function. Both doctors have also been working with Dr Roger Barker of the Centre for Brain Repair on Huntington’s disease models.

Photo credit: Soldiers by Heather Aitken via Flickr

Feature photo credit: Bussey & Saksida

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