Answer:
Explanation:
Alzheimer’s disease is a progressive neurodegenerative disease. It is characterized by the loss of memory, multiple cognitive impairments and changes in the personality and behaviour. It is the most common cause of dementia. At the cellular level, there are synaptic damage, mitochondrial abnormalities, inflammatory responses, hormonal changes and cell cycle impairment. It is a multifactorial disease caused by the mutations in amyloid-β protein precursor, presenilin 1 and 2 genes.
Thus, the imbalance of a variety of neurotransmitters such as glutamate, acetylcholine, dopamine and serotonin are present. The glutamatergic and cholinergic systems are involved in memory and cognition. Those systems are thus, involved in the progression of Alzheimer’s dementia.
The most important risk factors for Alzheimer’s disease are age, APOE-e4 and family history.
The various cellular changes in Alzheimer’s disease are due to the accumulation of amyloid-β and phosphorylated tau. Amyloid-β formed plaques may cause cell death by interfering with neurons communication at synapses. Tau protein blocks the transport of nutrients and other vital molecules inside neurons. In the presence of tau and toxic amyloid-β in the brain, the microglia cells are activated. Microglia has the role to eliminate the toxic proteins as well as dead cells. There are chronic inflammation and atrophy of the brain tissue. Glucose metabolism in the brain is as well impaired.
In Alzheimer’s dementia, there is a significant memory, thinking and behavioural impairment that disrupts the daily activities.
