Down syndrome (DS), caused by trisomy of chromosome 21, is marked by 
intellectual disability (ID) and early onset of Alzheimer's disease (AD) 
neuropathology including hippocampal cholinergic projection system degeneration. 
Here we determined the effects of age and maternal choline supplementation (MCS) 
on hippocampal cholinergic deficits in Ts65Dn mice compared to 2N mice 
sacrificed at 6-8 and 14-18 months of age. Ts65Dn mice and disomic (2N) 
littermates sacrificed at ages 6-8 and 14-18 mos were used for an aging study 
and Ts65Dn and 2N mice derived from Ts65Dn dams were maintained on either a 
choline-supplemented or a choline-controlled diet (conception to weaning) and 
examined at 14-18 mos for MCS studies. In the latter, mice were behaviorally 
tested on the radial arm Morris water maze (RAWM) and hippocampal tissue was 
examined for intensity of choline acetyltransferase (ChAT) immunoreactivity. 
Hippocampal ChAT activity was evaluated in a separate cohort. ChAT-positive 
fiber innervation was significantly higher in the hippocampus and dentate gyrus 
in Ts65Dn mice compared with 2N mice, independent of age or maternal diet. 
Similarly, hippocampal ChAT activity was significantly elevated in Ts65Dn mice 
compared to 2N mice, independent of maternal diet. A significant increase with 
age was seen in hippocampal cholinergic innervation of 2N mice, but not Ts65Dn 
mice. Degree of ChAT intensity correlated negatively with spatial memory ability 
in unsupplemented 2N and Ts65Dn mice, but positively in MCS 2N mice. The 
increased innervation produced by MCS appears to improve hippocampal function, 
making this a therapy that may be exploited for future translational approaches 
in human DS.