Transgenic Mice

Transgenic mouse models have been developed through the expression of mutated APP (or the overexpression of its wild type) to study the involvement of ^A-containing fragments in AD-type abnormalities. Among the many transgenic mice, the PDAPP mouse is one of the best characterized since it develops ^A accumulation in neocortex and hippocampus after 12 months of age. These mice show consistent pathological symptoms before ^A accumulates, thus suggesting that neuronal pathology may come from developmental abnormalities or that soluble ^A is responsible for these alterations. Namely, loss of dendritic arborizations leading to a reduction in the volume of the dentate gyrus is apparent as early as three months of age.

As in AD, the initial accumulation of ^A occurs in the enthorinal cortex and dentate gyrus, but in PDAPP mice a minimal neuronal death occurs, at variance with AD. In a mouse model with mutations of APP and presenilin 1, neuronal death is significant, and the selective vulnerability of neurons (e.g., the hippocampal CA1 pyramidal cells) is similar to the results found in AD patients. In this model, at variance with the PDAPP one, loss of neurons close to and in zones devoid of ßA deposits is the same, which suggests that aggregation of ßA into plaques does not necessarily imply neuron loss. Conceivably, it is clearly apparent that comparison of the results obtained from different transgenic mice may help to envisage the sequential events involved in age- and pathology-related alterations of the brain.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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