Behavioral and EEG changes in male 5xFAD mice

Area of Science:

• Neuroscience
• Genetics
• Animal Models

Background:

• Transgenic animal models are crucial for studying Alzheimer's disease (AD) pathophysiology and cognitive dysfunction.
• The 5xFAD mouse model exhibits early amyloid plaque deposition, overexpressing human amyloid precursor protein (APP) and presenilin 1 (PS1).
• This leads to accelerated accumulation of amyloid-beta (Aβ) peptides, particularly the Aβ42 species.

Purpose of the Study:

• To investigate the behavioral and functional characteristics of male 5xFAD mice, as most previous studies focused on females.
• To assess cognitive functions, anxiety levels, and exploratory behavior in male 5xFAD mice.
• To analyze electroencephalogram (EEG) patterns and sleep architecture in male 5xFAD mice.

Main Methods:

• Behavioral testing including elevated plus maze, open field exploration, and Morris water maze.
• Electroencephalogram (EEG) recordings in awake and sleeping male 5xFAD mice and wild-type controls.
• Analysis of EEG frequency bands (delta, theta, alpha, beta, gamma, subdelta) and sleep stages (REM sleep).

Main Results:

• Male 5xFAD mice displayed decreased anxiety, reduced locomotion and exploration, and impaired learning and memory starting at 9 months of age.
• EEG recordings at 6 months showed decreased delta, theta, alpha, beta, and gamma frequencies, with increased subdelta frequency.
• Reduced rapid eye movement (REM) sleep was observed in relation to total sleep time.

Conclusions:

• Male 5xFAD mice develop early functional disturbances and subsequent behavioral deficits relevant to Alzheimer's disease.
• These findings establish male 5xFAD mice as a suitable model for investigating AD mechanisms.
• The study underscores the importance of sex-specific characterization in AD mouse models.