The mouse model of Down syndrome Ts65Dn presents visual deficits as assessed by pattern visual evoked potentials.

Purpose: The Ts65Dn mouse is the most complete widely available animal model of Down syndrome (DS). Quantitative information was generated about visual function in the Ts65Dn mouse by investigating their visual capabilities by means of electroretinography (ERG) and patterned visual evoked potentials (pVEPs).

Methods: pVEPs were recorded directly from specific regions of the binocular visual cortex of anesthetized mice in response to horizontal sinusoidal gratings of different spatial frequency, contrast, and luminance generated by a specialized video card and presented on a 21-in.

Otitis media in a mouse model for Down syndrome.

The Ts65Dn mouse shares many phenotypic characteristics of human Down syndrome. Here, we report that otitis media, characterized by effusion in the middle ear and hearing loss, was prevalent in Ts65Dn mice. Of the 53 Ts65Dn mice tested, 81.

Behavioral validation of the Ts65Dn mouse model for Down syndrome of a genetic background free of the retinal degeneration mutation Pde6b(rd1).

The Ts65Dn mouse is the most studied and complete aneuploid model of Down syndrome (DS) widely available. As a model for human trisomy 21, these mice display many attractive features, including performance deficits in different behavioral tasks, alterations in synaptic plasticity and adult neurogenesis, motor dysfunction, and age-dependent cholinergic neurodegeneration. Currently, Ts65Dn mice are maintained on a genetic background that leads to blindness in about 25% of their offspring, because it segregates for the retinal degeneration 1 (Pde6b(rd1)) mutation of C3H/HeSnJ.

Synaptojanin 1-linked phosphoinositide dyshomeostasis and cognitive deficits in mouse models of Down's syndrome.

Phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P(2)] is a signaling phospholipid implicated in a wide variety of cellular functions. At synapses, where normal PtdIns(4,5)P(2) balance is required for proper neurotransmission, the phosphoinositide phosphatase synaptojanin 1 is a key regulator of its metabolism. The underlying gene, SYNJ1, maps to human chromosome 21 and is thus a candidate for involvement in Down's syndrome (DS), a complex disorder resulting from the overexpression of trisomic genes.

Behavioral, cognitive and biochemical responses to different environmental conditions in male Ts65Dn mice, a model of Down syndrome.

Ts65Dn mouse is the most widely accepted model for Down syndrome. We previously showed that environmental enrichment improved spatial learning in female but deteriorated it in male Ts65Dn mice. This study analyzed the factors contributing to the disturbed cognition of male Ts65Dn mice after enriched housing, by allocating male control and Ts65Dn mice in four conditions after weaning: small (n = 2-3) and large group (n = 8-10) housing, and enriched housing in small (2-3) and large groups (8-10).

Operant conditioning in the Ts65Dn mouse: learning.

Ts65Dn and littermate controls were trained to respond (nose-poke) under operant schedules of reinforcement. A small difference was observed in the initial operant training of the Ts65Dn mouse that disappeared with training under a fixed-ratio 15 schedule of milk presentation. No difference was observed in a position reversal task in which mice initially trained to respond upon one photocell had to learn to respond on a previously inactive photocell.

Quantitative PCR genotyping assay for the Ts65Dn mouse model of Down syndrome.

The Ts65Dn mouse is a segmentally trisomic model for Down syndrome. Until now, Ts65Dn mice have been identified by the laborious methods of either chromosomal analysis of cultured peripheral lymphocytes or fluorescent in situ hybridization (FISH). We report here a quantitative PCR method for genotyping Ts65Dn mice, as well as a phenotypic description for visually preclassifying mice to be genotyped.

Differential effects of environmental enrichment on behavior and learning of male and female Ts65Dn mice, a model for Down syndrome.

We have assessed the effects of enriched environment (EE) upon behavioral and cognitive performances of partially trisomic Ts65Dn (TS) mice and their control (CO) littermates. Enriched environment was applied to pups for 7 weeks after weaning. Circadian spontaneous activity (actimetry), exploratory behavior (hole board), activity in the open field and spatial memory (Morris Water Maze, repeated acquisition and cued paradigms) were analyzed in 86 female and 75 male mice, starting 15 days after completing enrichment.