The emergence of the Alzheimer's disease

In order to study the disease, mice transgenic (genetically modified) are used. In some mice, the gene encoding the Tau protein is mutated. Among others, the gene encoding the protein amyloid that is transferred. Some mice will suffer mutations in both genes.

Mice that had a mutation in the gene encoding the protein Tau show an appearance of the disease shortly pronounced. Mice that had a mutation in the gene encoding the protein amyloid behave like healthy mice. The mice with mutated genes on the two show a disease exacerbated, well defined.

This does not happen necessarily in the same way in humans, but it shows that amyloid plaques potentiate the disease. The neurofibrilles appear at first, and when the amyloid plaques appear, the disease is triggered.

The middle intracellular

In the microtubules, protein Tau placed perpendicular manner and allow the rigidity of microtubules in axonal transport.

From time to time, subject to a normal protein Tau stand out. They are replaced and degraded rapidly.
But in an affected Alzheimer's disease, Tau proteins were created from the microtubules, and fall in the intracellular environment. They are not all degraded and will therefore aggregate. That will train neurofibrilles. The neurofibrilles too important block the functioning of the neuron and do not allow the proper axonal transport. The neurofibrilles compress the neuron and cause neuronal death.

There are several explanations to the posting of Tau proteins:

* Phosphorylation: this feature allows the protein. Tau protein is phosphorylated and very little when it is very phosphorylated, it can not focus on the microtubules. These are proteins that stand out and accumulate in forming neurofibrilles. In this explanation, the cause of the increase in phosphorylation is unknown.
* Cuts proteolytiques tau proteins, which appear to intervene early and would be an event concomiant the hyperphosphorylation of these proteins.
* Genetic factors as for all the proteins, there is a gene that encodes the protein Tau. The gene may have different alleles in September. These seven alleles can be classified into two categories:
o those three reasons R
o those four grounds R.

Tau proteins derived alleles three reasons R have a fixation less important than proteins derived alleles to four reasons.