Memory deficits in transgenic McGill-R-Thy1-APP hemizygous rats

D. SALAS; F. FILIPPIN; E. KORNSIUK; P. CANAL; A. DI TOMAS LIORO; S. DOCARMO; A.C. CUELLO; M.V. BAEZ; D. JERUSALINSKY

Cordoba

Congreso; XXXIII Congreso anual de la Sociedad Argentina de Neurociencias; 2018

Sociedad Argentina de Neurociencias

McGill-R-Thy1-APP Wistar transgenic (Tg) rats, with human APP under the Thy1.2 promoter,bearing the Swedish and Indiana mutations corresponding to familial AD in homozygouscondition, had been reported to show significant cognition deficits at 3 months of age. On theother hand, hemizygous Tg rats show a more subtle phenotype. In this work, 6 and 13 month oldhemizygous Tg males and their WT litter mates rats were individually left to freely explore an openfield (OF) for 5 min and tested at 24 h; the numbers of crosses in the floor were recorded. Therewere no differences between WT and Tg groups during the training and the number of crossessignificantly decreased in the test compared with training. Rats were then trained in an inhibitoryavoidance task (IA) of a mild electric foot shock and tested at 24 h to evaluate long-term memory(LTM). Latency to go accross a door to get into a dark compartment where the rat will get theshock, was recorded. There were no significant differences in training latencies between animalgroups. 24 h later, test latencies were significantly higher than training latencies for WT rats, whilethere were no significant differences for Tg rats. Therefore, both Tg and WT rats are able tohabituate to the OF, keeping LTM; on the other hand, WT animals learned and remembered the IAat 24 h, while the Tg were not able to remember it, evidencing deficits in these sort of associativememory involving aversive and spatial components.