Olfactory bulb stimulation mitigates Alzheimer's-like disease progression

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Alzheimer's disease (AD) poses a significant challenge, with deep brain stimulation (DBS) showing potential but limited by invasiveness.
• The olfactory bulb (OB), affected early in AD and connected to memory centers, presents a promising, accessible target for intervention.
• Restoring neural activity in memory circuits is crucial for mitigating AD progression.

Purpose of the Study:

• To investigate the effects of olfactory bulb electrical stimulation on working memory in an amyloid beta (Aβ) rat model of AD.
• To assess pathological and electrophysiological changes in key brain regions, including the OB, medial prefrontal cortex, hippocampus, and entorhinal cortex.

Main Methods:

• Male Wistar rats modeling Alzheimer's-like disease received daily 1-hour bilateral OB electrical stimulation for 18 days.
• Histological, behavioral, and local field potential analyses were conducted post-stimulation.
• Electrode implantation targeted specific brain regions for stimulation and recording.

Main Results:

• Olfactory bulb stimulation effectively counteracted amyloid beta plaque accumulation.
• Working memory impairments associated with AD were prevented by OB stimulation.
• Enhanced power across frequency bands and gamma-band functional connectivity were observed in stimulated regions during memory tasks.

Conclusions:

• Olfactory pathway stimulation shows potential for modulating deep memory networks in Alzheimer's disease treatment.
• The accessibility of the olfactory pathway via the nasal cavity supports the development of minimally invasive therapeutic strategies.
• This preclinical study provides a foundation for novel, less invasive interventions for AD targeting the olfactory system.