Researchers find that damage to the brain’s salience network leads to mood and behavioral changes, offering new insights into Alzheimer’s progression.

A recent study from the University of Michigan has shed light on how tau pathology, a hallmark of Alzheimer’s disease, contributes to mild behavioral impairment (MBI).

This condition, characterized by mood and behavioral changes, often appears before cognitive decline. The research focused on how tau impacts the brain’s salience network, which is responsible for processing emotional stimuli and switching between different modes of thinking. Disruption in this network, according to the study, is key to understanding how Alzheimer’s pathology leads to neuropsychiatric symptoms like anxiety, irritability, and social withdrawal.

The researchers analyzed data from 128 participants with either mild cognitive impairment or early-stage Alzheimer’s and found that the salience network’s integrity plays a critical role in moderating the behavioral effects of tau accumulation. The study reveals that while tau accumulation in the brain does not directly cause behavioral symptoms, it significantly impacts the salience network, which in turn triggers behavioral changes.

This study marks a significant step forward in Alzheimer’s research by emphasizing the connection between brain network function and neuropsychiatric symptoms, a relationship that had not been fully understood before. The findings suggest that targeting brain network disruptions might provide new avenues for diagnosing and treating the early stages of Alzheimer’s disease, particularly in those who show behavioral changes before cognitive symptoms become evident.

Understanding the role of the salience network could lead to earlier interventions aimed at slowing down or preventing the progression of these behavioral impairments, offering hope for improving the quality of life for those at risk of Alzheimer’s disease. With Alzheimer’s affecting millions worldwide, this research provides a new perspective on how the disease manifests and progresses, offering valuable insights for future treatments.

Source: “Salience network segregation mediates the effect of tau pathology on mild behavioral impairment,” Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.14229