La. Hyde et al., Ts65Dn mice, a model for Down syndrome, have deficits in context discrimination learning suggesting impaired hippocampal function, BEH BRA RES, 118(1), 2001, pp. 53-60
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 l
earning tasks that require an intact hippocampus. Context discrimination le
arning is dependent on the dorsal hippocampus in mice. In this task, mice l
earn 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 con
trols behaved similarly to sham lesioned mice. Therefore: Ts65Dn mice have
learning deficits in a hippocampal dependent task that may be related to th
e loss of cholinergic input to the hippocampus, which occurs after 6 months
of age. (C) 2001 Elsevier Science B.V. All rights reserved.