The touchscreen operant platform for testing learning and memory in rats and mice

Abstract

Summary An increasingly popular method of assessing cognitive functions in rodents is the automated touchscreen platform, on which a number of different cognitive tests can be run in a manner very similar to touchscreen methods currently used to test human subjects. This methodology is low stress (using appetitive, rather than aversive reinforcement), has high translational potential, and lends itself to a high degree of standardisation and throughput. Applications include the study of cognition in rodent models of psychiatric and neurodegenerative diseases (e.g., Alzheimer’s disease, schizophrenia, Huntington’s disease, frontotemporal dementia), and characterisation of the role of select brain regions, neurotransmitter systems and genes in rodents. This protocol describes how to perform four touchscreen assays of learning and memory: Visual Discrimination, Object-Location Paired-Associates Learning, Visuomotor Conditional Learning and Autoshaping. It is accompanied by two further protocols using the touchscreen platform to assess executive function, working memory and pattern separation.

Stress facilitates late reversal learning using a touchscreen-based visual discrimination procedure in male Long Evans rats

“…The visual discrimination and reversal learning procedures closely followed those recommended by the manufacturer and optimized in Professor Timothy Bussey's laboratory [18,19,21]. Following the third day of food restriction, rats were put in the touchscreen operant chambers and habituated for 30 min.…”

“…Previous studies have used two operant paradigms for assessing the effects of acute stress on reversal learning. In two studies [11,12], a touchscreen-based discrimination task [17][18][19] that took several weeks to complete was used in mice. After being trained on a discrimination task for food reward and before initiating a reversal of the discrimination, mice were subjected to 3 days of swim stress.…”

Optimization of the touchscreen paired-associate learning (PAL) task for mice and its dorsal hippocampal dependency

“…We used the Bussey-Saksida touch screen operant chamber (#80614) for touch screen testing (Campden Instruments Ltd, UK), with previously reported chamber settings (Horner et al 2013). Stimuli of the same size and images (flower, spider, and airplane) were used in the sPAL, dPAL, and 2-object sPAL tasks.…”

“…Basically, these three stages of the pretraining were performed according to the protocols in previous studies (Horner et al 2013;Nithianantharajah et al 2013). In the initial touch training, mice gained the liquid reward (8 µl) by touching stimuli of various shapes appearing on one of the three windows of the screen or waiting for 30 s. The initial touch stage was performed for only 1 day for all mice.…”

“…The touchscreen testing method was developed as a novel automated behavioral procedure for assessing various cognitive functions in rodents (Bussey et al 1994(Bussey et al , 2008Brigman et al 2013) and the PAL task is one of the most frequently used tasks in this system. Because the PAL task is performed in this automated system, many of the advantages of this system are those of the PAL task: more reliable data, nonaversive experiments, and high applicability of the findings to humans (Bussey et al 2012;Horner et al 2013;Nithianantharajah et al 2015).…”