Is ammonia a pathogenetic factor in Alzheimer's disease?

Area of Science:

• Neuroscience
• Biochemistry
• Pathology

Background:

• Dementia of the Alzheimer type (DAT) is a progressive neurodegenerative disorder.
• The role of ammonia in DAT pathogenesis is increasingly investigated.
• Hyperammonemia is linked to various brain dysfunctions.

Purpose of the Study:

• To review experimental evidence supporting ammonia's role in DAT.
• To explore biochemical and cellular mechanisms of ammonia's impact on the brain.

Main Methods:

• Review of existing experimental data on ammonia and DAT.
• Analysis of biochemical and cellular changes associated with hyperammonemia in DAT brains.

Main Results:

• Hyperammonemia induces brain dysfunctions including astrocytosis, impaired glucose utilization, and altered energy metabolism.
• Ammonia affects neurotransmission, increasing excitability and glutamate release.
• Ammonia may interfere with lysosomal protein processing, relevant to amyloid precursor protein metabolism.

Conclusions:

• Ammonia is not a primary cause but a contributing factor to DAT manifestations and progression.
• Elevated ammonia levels in DAT patients warrant consideration for therapeutic interventions.
• Targeting ammonia levels could offer novel strategies for ameliorating DAT symptoms and slowing disease progression.