Hippocampus and its involvement in Alzheimer's disease: a review

Area of Science:

• Neuroscience
• Neurobiology
• Gerontology

Background:

• The hippocampus, a key brain region for learning and memory, is significantly impacted by Alzheimer's disease (AD).
• Early AD stages involve rapid hippocampal tissue loss and functional disconnection, with medial temporal and hippocampal atrophy serving as MRI markers.
• Reduced sirtuin (SIRT) expression in hippocampal neurons impairs cognitive functions like spatial learning and recent memory.

Purpose of the Study:

• To explore the hippocampus's role in learning, memory, and its vulnerability in Alzheimer's disease.
• To investigate the factors influencing neural stem cell (NSC) function within the hippocampus.
• To highlight the potential of a pro-neurogenic lifestyle in mitigating neurodegeneration.

Main Methods:

• Review of existing literature on hippocampal structure and function.
• Analysis of the impact of Alzheimer's disease on hippocampal integrity.
• Examination of intrinsic and extrinsic factors affecting adult neurogenesis in the hippocampus.

Main Results:

• The hippocampus is crucial for episodic memory generation but susceptible to AD-induced atrophy and functional decline.
• Sirtuin (SIRT) expression is vital for hippocampal neuron function and cognitive processes.
• Microglia exhibit heightened immunological activity in the hippocampus, influencing the neural environment.
• Intrinsic factors (hormones, glia, vascular supply) and extrinsic factors (diet, physical activity) modulate hippocampal neural stem cell (NSC) function.

Conclusions:

• The hippocampus's vulnerability to Alzheimer's disease necessitates understanding factors that protect its structure and function.
• Modulating intrinsic and extrinsic factors can influence hippocampal neurogenesis and potentially delay neurodegeneration.
• Adopting a pro-neurogenic lifestyle may be a viable strategy to counteract cognitive decline associated with aging and neurodegenerative diseases.