Ts65Dn mice, a model for Down syndrome, have deficits in context discrimination learning suggesting impaired hippocampal function

• Published in: Behavioural brain research Vol. 118; no. 1; pp. 53 - 60
• Main Authors: Hyde, Lynn A, Frisone, Deborah F, Crnic, Linda S
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 08.01.2001; Elsevier Science
• Subjects: Age Factors; Animal; Animals; Biological and medical sciences; Discrimination Learning; Disease Models, Animal; Down Syndrome - pathology; Down Syndrome - psychology; Fear; Fear related behaviors; Fundamental and applied biological sciences. Psychology; Genotype; Hippocampal dependent learning; Hippocampus - physiology; Hippocampus - physiopathology; Human chromosome 21; Learning; Learning. Memory; Male; Mice; Mice, Neurologic Mutants; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Segmental trisomy; Shock sensitivity; Video analysis of behavior; Fear related behaviors; Shock sensitivity; Video analysis of behavior; Hippocampal dependent learning; Human chromosome 21; Segmental trisomy; Chromosomal aberration; Context; Animal model; Trisomy; Rodentia; Central nervous system; Aneuploidy; Down syndrome; Experimental study; Learning; Vertebrata; Mammalia; Acquisition process; Mouse; Animal; Tonic immobility; Hippocampus; Brain (vertebrata)
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/S0166-4328(00)00313-2

The Ts65Dn mouse is segmentally trisomic for a part of mouse chromosome 16 and is a genetic model for Down syndrome and Alzheimer's disease. Although many studies have examined the learning and memory processes in Ts65Dn mice, it has yet to be determined if Ts65Dn mice are specifically impaired in learning tasks that require an intact hippocampus. Context discrimination learning is dependent on the dorsal hippocampus in mice. In this task, mice learn to discriminate two similar contexts, one of which is associated with foot shock. In the current study, Ts65Dn mice learned almost identically to what has been reported for mice with dorsal hippocampal lesions, while controls behaved similarly to sham lesioned mice. Therefore, Ts65Dn mice have learning deficits in a hippocampal dependent task that may be related to the loss of cholinergic input to the hippocampus, which occurs after 6 months of age.