IMPAIRED SPATIAL WORKING AND REFERENCE MEMORY IN SEGMENTAL TRISOMY (TS65DN) MICE

To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65D n) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spati al working and reference memory using a 12-arm radial maze (RAM). Ts65 Dn mice made a greater number of reference memory errors across trials compared to control mice. Both genotypes showed improvement across tr ials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working memory errors on the RAM, and in con trast to control mice, did not improve across trials, always performin g at near-chance levels. These results provide evidence for both spati al working and reference memory deficits in Ts65Dn mice, characteristi cs of cognitive dysfunction. (C) 1998 Elsevier Science B.V.