Spatial discrimination and visual discrimination: two methods evaluating learning and memory in juvenile Göttingen minipigs.

Two methods investigating learning and memory in juvenile Göttingen minipigs were evaluated for potential use in preclinical toxicity testing. Twelve minipigs were tested using a spatial hole-board discrimination test including a learning phase and two memory phases. Five minipigs were tested in a visual discrimination test. The juvenile minipigs were able to learn the spatial hole-board discrimination test and showed improved working and reference memory during the learning phase. Performance in the memory phases was affected by the retention intervals, but the minipigs were able to remember the concept of the test in both memory phases. Working memory and reference memory were significantly improved in the last trials of the memory phases. In the visual discrimination test, the minipigs learned to discriminate between the three figures presented to them within 9-14 sessions. For the memory test, all minipigs performed 9/12 correct choices or better. Juvenile Göttingen minipigs are able to learn to perform in a spatial hole-board discrimination test as well as in a visual discrimination test, showing an increase in performance over time. Both tests have considerable scope to assess learning and memory of pigs, and we seem to have succeeded in establishing two test systems suitable for performing preclinical toxicity testing in juvenile minipigs.