Preserved modular network organization in the sedated rat brain.

Area of Science:

• Neuroscience
• Systems Neuroscience
• Pre-clinical Imaging

Background:

• Resting-state functional connectivity (FC) magnetic resonance imaging (rs-fMRI) is increasingly translated to rodent models for pre-clinical research.
• Understanding the normal organizational architecture of rodent brain functional connectivity networks (FCNs) is essential before studying disease states.

Purpose of the Study:

• To characterize the modular organization and centrality of brain regions in Sprague-Dawley rats using rs-fMRI.
• To assess the reproducibility of FCN properties under medetomidine sedation.

Main Methods:

• rs-fMRI was performed on 40 Sprague-Dawley rats under medetomidine sedation.
• Complex network analysis was applied to construct FCNs based on Pearson partial correlation of 36 brain regions.
• Modular organization and network hubs were evaluated.

Main Results:

• The rat FCN exhibits a modular architecture with six reproducible modules.
• Network hubs connecting diverse brain regions were identified.
• The modular organization under medetomidine sedation is preserved and resembles findings in conscious rats, contrasting with deep anesthesia.

Conclusions:

• Sedated rat brain FCNs display a reproducible modular structure.
• This study provides a foundational understanding of rodent brain network organization under sedation.
• The findings support the use of rs-fMRI in rodent models for pre-clinical neuroscience research.