Spatial learning in the guinea pig: cued versus non-cued learning, sex differences, and comparison with rats

This paper provides the first report of spatial learning in guinea pigs usi ng the Morris water maze (MWM). Male and female guinea pigs were trained fo r 5 consecutive days (8 trials/day; acquisition phase) in either the visibl e (cued) or the hidden (non-cued) platform version of the MWM. In both test s, guinea pigs learned to navigate to the escape platform, as indicated by a decrease in escape latency over the 5 training days. There were no sex di fferences in either test version. A comparison of guinea pigs and male Wist ar rats showed that performance during acquisition training was not differe nt for the two species in the visible platform test, but rats performed bet ter during the early training days in the hidden platform test. A retention test (probe trial) was given 5 days after the last acquisition training da y, Again, there was no sex difference, and no difference between guinea pig s and rats. Finally, acquisition of a new escape response to a shifted plat form location was equivalent for rats and guinea pigs of both sexes. These results demonstrate that guinea pigs show robust cued and non-cued learning in the MWM. Both acquisition and retention performance in guinea pigs is s imilar to that in rats, even though rats appear to have a slight advantage in the acquisition of non-cued, spatial information in this test. We conclu de that the MWM provides a valuable paradigm to assess behavior and learnin g/memory in the guinea pig. (C) 2001 Elsevier Science B.V. All rights reser ved.