Final answer:
Insoluble plaques in Alzheimer's disease are caused by the misfolding of β-amyloid proteins from a soluble α-helix to sticky β-pleated sheets, leading to the formation of amyloid plaques and the hallmark neurodegeneration of Alzheimer's.
Step-by-step explanation:
How Do Insoluble Plaques in Neurons Occur in Alzheimer's Disease?
Insoluble plaques in neurons are a hallmark of Alzheimer's disease and occur due to the misfolding of proteins. Normally, proteins like β-amyloid (Aβ) are soluble and in an α-helix form. In Alzheimer's, these proteins change into β-pleated sheets, which are sticky and tend to aggregate. Over time, these aggregated proteins form amyloid plaques, which are found between neurons and are associated with the disease's characteristic neurodegeneration and memory impairment. The development of these plaques is part of a broader category called 'proteopathy', where misfolded proteins accumulate and become toxic.
The presence of Aβ not only leads to plaque formation but also impacts glutamate transmission, increasing the risk of excitotoxicity which further harms neuronal function. In Alzheimer's, the function of glutamate transporters is impaired and synaptic connections are lost due to the internalization of AMPA receptors. These changes contribute significantly to the cognitive decline seen in patients with Alzheimer's.
Understanding the formation of insoluble plaques in Alzheimer's provides insight into the mechanisms of neural degeneration and opens potential avenues for treatment strategies that could interfere with the abnormal protein accumulation or their production within the cell.