Aβ(42) induced MRI changes in aged rabbit brain resembles AD brain

Area of Science:

• Neuroscience
• Neurodegenerative Diseases
• Biomedical Imaging

Background:

• Alzheimer's disease (AD) is a leading cause of dementia, characterized by brain atrophy and volume loss.
• Amyloid-beta (Aβ) deposition is a key pathological hallmark of AD and is correlated with brain atrophy.
• Structural brain imaging, such as Magnetic Resonance Imaging (MRI), is crucial for assessing neuroanatomical alterations.

Purpose of the Study:

• To investigate the causal role of Aβ in inducing brain structural changes.
• To compare Aβ-induced neuroanatomical alterations in an aged rabbit model with human AD brain changes.
• To elucidate the specific brain regions affected by Aβ deposition using MRI.

Main Methods:

• Chronic intracerebral injection of Aβ(1-42) or saline into aged rabbits (n=10 per group).
• Serial MRI scans were performed before and 45 days after injection to measure brain structure.
• Comparative MRI analysis was conducted on human AD patients (n=10) and healthy controls (n=10).

Main Results:

• Aβ(1-42) injection in rabbits led to significant reductions in frontal lobe and hippocampus thickness, and increased lateral ventricle volume.
• Human AD brains showed significant reductions in frontal lobe and hippocampus thickness compared to controls.
• Brain atrophy patterns in the frontal lobe and hippocampus of rabbits correlated with those observed in human AD brains.

Conclusions:

• Aβ(1-42) administration induces structural brain changes in rabbits that partially mimic human Alzheimer's disease.
• The frontal lobe and hippocampus are critical regions affected by Aβ-induced neurodegeneration in both rabbits and humans.
• The aged rabbit model provides a valuable platform for studying Aβ-related brain atrophy and potential therapeutic interventions for AD.