# Age-related alterations in functional and structural networks in the brain in macaque monkeys

## TL;DR

This study explores how brain networks in macaques change with age, revealing differences in structural and functional connectivity.

## Contribution

The study identifies age-related changes in resting-state networks in macaques using both functional and structural perspectives.

## Key findings

- Structural connectivity in resting-state networks decreases with age in macaques.
- Functional connectivity in resting-state networks increases with age.
- Low-frequency neural activity in resting-state networks becomes more active with age.

## Abstract

Resting-state networks (RSNs) have been used as biomarkers of brain diseases and cognitive performance. However, age-related changes in the RSNs of macaques, a representative animal model, are still not fully understood. In this study, we measured the RSNs in macaques aged 3–20 years and investigated the age-related changes from both functional and structural perspectives. The proportion of structural connectivity in the RSNs relative to the total fibers in the whole brain significantly decreased in aged macaques, whereas functional connectivity showed an increasing trend with age. Additionally, the amplitude of low-frequency fluctuations tended to increase with age, indicating that resting-state neural activity may be more active in the RSNs may increase with age. These results indicate that structural and functional alterations in typical RSNs are age-dependent and can be a marker of aging in the macaque’s brain.