Novel Social Stimulation Ameliorates Memory Deficit in Alzheimer's Disease Model through Activating α-Secretase

Area of Science:

• Neuroscience
• Dementia Research
• Alzheimer's Disease Pathophysiology

Background:

• Alzheimer's disease (AD) is the most common dementia, characterized by cognitive decline.
• Social connections are known to protect against dementia, but the underlying mechanisms are unclear.
• Understanding how social interactions benefit cognitive function in AD is crucial for developing interventions.

Purpose of the Study:

• To investigate the molecular mechanisms by which social interactions influence cognitive function in Alzheimer's disease.
• To explore the role of alpha-secretase pathway in mediating the effects of social stimulation on AD pathology and cognitive performance.
• To determine if novel social interaction can serve as a preventative or therapeutic strategy for early-stage AD.

Main Methods:

• Utilized wild-type (WT) mice and a FAD4T mouse model of Alzheimer's disease.
• Administered single novel social (SNS) and multiple novel social (MNS) stimulation.
• Measured c-Fos expression, ADAM10/17 and sAPPα protein levels, hippocampal neuron activity, and synaptic plasticity.
• Assessed memory impairments and amyloid-beta (Aβ) levels.
• Investigated the effect of an alpha-secretase inhibitor on SNS-induced changes.

Main Results:

• SNS stimulation increased c-Fos expression and mature ADAM10/17 and sAPPα levels in the ventral hippocampus (vHPC) of WT mice, dependent on dCA2 neuron activity and vHPC NMDAR.
• Similar changes were observed in FAD4T mice following SNS, and these were reversible with an alpha-secretase inhibitor.
• MNS stimulation improved synaptic plasticity and memory in both male and female FAD4T mice, associated with alpha-secretase activation and reduced Aβ.

Conclusions:

• Novel social interaction activates the alpha-secretase pathway, influencing neuronal activity and protein processing in the hippocampus.
• This pathway modulation by social stimulation ameliorates cognitive deficits and reduces amyloid pathology in an AD mouse model.
• Novel social interaction and alpha-secretase activation represent promising preventative and therapeutic targets for early-stage Alzheimer's disease.