Mathematical Model Shows How Sleep May Affect Amyloid-β Fibrillization

Area of Science:

• Neuroscience
• Biophysics
• Mathematical Biology

Background:

• Amyloid-beta (Aβ) fiber deposition is central to Alzheimer's disease (AD).
• Current understanding of Aβ plaque formation lacks long-timescale models integrating neural activity and clearance mechanisms.
• No existing models incorporate circadian rhythm's impact on Aβ progression due to sleep-wake cycle disruption.

Purpose of the Study:

• To develop a minimal mathematical model of Aβ fibrillization to investigate AD onset over long timescales.
• To explore the role of circadian rhythm and sleep-wake cycle in Aβ accumulation.
• To identify potential intervention strategies targeting Aβ production rates.

Main Methods:

• Development of a minimal mathematical model for Aβ fibrillization.
• Integration of circadian rhythm and sleep-wake cycle dynamics into the model.
• Analysis of phase transitions from soluble Aβ (sAβ) to fibrillar Aβ (fAβ) domination.

Main Results:

• The diseased state in AD is characterized by a phase transition from sAβ to fAβ domination, triggered by exceeding a critical sAβ production rate.
• Aβ accumulation is significantly influenced by the regulation of the sleep-wake cycle, as indicated by the model.
• Disruption of the sleep-wake cycle exacerbates fAβ accumulation, underscoring the importance of sleep hygiene.

Conclusions:

• Aβ fibrillization and AD onset are critically dependent on the balance between production and clearance, influenced by neural activity patterns.
• Circadian regulation and sleep quality play a crucial role in modulating Aβ plaque formation.
• Modifying the sAβ production rate presents a potential therapeutic avenue for reducing Aβ accumulation in AD.