Pharmacological Manipulation of a Rodent Paired Associates Learning (Pal) Paradigm, and other Tasks for Use in Disease Research

Paired Associated learning (PAL) as part of the Cambridge Neurological Test Battery (CANTAB) is a task of great potential for disease research. The initial interest in this task was sparked by studies of patients with Alzheimer’s disease (AD) or mild cognitive impairment (MCI), often viewed as a prodromal form of AD. AD patients were highly impaired on PAL, more importantly, so were a sub-population of MCI patients. Subsequent studies would reveal that this “impaired” sub-population of MCI patients showed a much higher conversion rate to AD than the rest of the cohort. Through the use of PAL and related tests, researchers were able to predict who would, and who would not convert to AD from an at-risk population several years earlier than with other available clinical tests (1). While the link between PAL and AD was being established, another line of research began to associate PAL with schizophrenia. Specifically patients suffering from first episode psychosis were found to be impaired in PAL. Furthermore performance on PAL was found to be more predictive of global cognitive function in schizophrenia than the extra dimensional / intra dimensional shift (ED/ID) task, often considered a gold standard for research into cognitive impairments in schizophrenia (2). As such this one task appears to have great value in researching cognitive impairments associated with AD and schizophrenia, and a pre-clinical model of this assay would be of great utility.