Establishment of a rodent cooperation assay as a model of social cognition.

INTRODUCTION: Impaired cooperative skills form a characteristic symptom in autism, which lacks adequate treatment. The objective of this study was to establish a rat cooperation assay which fits the feasibility and capacity requirements of drug development.

METHODS: Long-Evans and Lister Hooded rats were trained in pairs to simultaneously perform nose-pokes (within 1 s) for reward in a Skinner box equipped with two nose-poke modules. Conditioning took place first with naive-naive pairs, then with naive-experienced and finally with experienced-experienced pairs, when the task was familiar for both rats. In a control experiment, experienced Lister-hooded pairs were tested under the learnt schedule but without the possibility to communicate with each other.

RESULTS: Rats were able to learn the task in 8-15 sessions. Experienced-experienced Long-Evans pairs completed the training significantly faster than the other pairs Analysis of the nose-poke latency data, sample video-recordings and the significantly decreased performance of rats in the control experiment suggested that the animals solved the task via real cooperation.

DISCUSSION: The newly developed rat cooperation model is quick and has sufficiently high throughput, therefore it may be used in the drug development of putative social cognitive enhancer compounds.