A familial Danish dementia rat shows impaired presynaptic and postsynaptic glutamatergic transmission.

Familial British dementia and familial Danish dementia are neurodegenerative disorders caused by mutations in the gene integral membrane protein 2B (ITM2b) encoding BRI2, which tunes excitatory synaptic transmission at both presynaptic and postsynaptic termini. In addition, BRI2 interacts with and modulates proteolytic processing of amyloid-β precursor protein (APP), whose mutations cause familial forms of Alzheimer's disease (AD) (familial AD). To study the pathogenic mechanisms triggered by the Danish mutation, we generated rats carrying the Danish mutation in the rat Itm2b gene (Itm2b rats).

Microglia Alzheimer-linked variant enhances excitatory transmission and reduces LTP via increased TNF-α levels.

To study the mechanisms by which the p.R47H variant of the microglia gene and Alzheimer's disease (AD) risk factor TREM2 increases dementia risk, we created KI rats. rats were engineered to produce human Aβ to define human-Aβ-dependent and -independent pathogenic mechanisms triggered by this variant.

Opposite changes in APP processing and human Aβ levels in rats carrying either a protective or a pathogenic APP mutation.

Cleavage of APP by BACE1/β-secretase initiates the amyloidogenic cascade leading to Amyloid-β (Aβ) production. α-Secretase initiates the non-amyloidogenic pathway preventing Aβ production. Several mutations cause familial Alzheimer's disease (AD), while the Icelandic mutation near the BACE1-cleavage site protects from sporadic dementia, emphasizing APP's role in dementia pathogenesis.