Resting-state functional connectivity in the rat cervical spinal cord at 9.4 T

Area of Science:

• Neuroscience
• Biomedical Imaging
• Functional MRI

Background:

• Resting-state functional MRI (fMRI) is widely used to study cortical functional connectivity.
• Translating fMRI to the spinal cord is less common, despite its crucial role in the central nervous system.
• Previous research demonstrated spinal cord functional connectivity in humans and nonhuman primates, but not in rodents.

Purpose of the Study:

• To investigate the detectability of resting-state functional connectivity within the rat spinal cord using fMRI.
• To identify and characterize functional connectivity patterns in the cervical spinal cord (C4-C7) of rats.

Main Methods:

• Resting-state fMRI scans were performed on live anesthetized rats at 9.4 Tesla.
• Image quality was assessed.
• Quantitative analyses were conducted to derive functional connectivity measures between spinal cord gray matter horns.

Main Results:

• Robust and statistically significant resting-state functional connectivity patterns were observed between gray matter horns.
• Dorsal-dorsal and ventral-ventral connectivity were the most prominent patterns.
• Moderate reproducibility was found in bilateral sensory and motor networks.

Conclusions:

• This study provides the first evidence of detectable resting-state functional circuits within the gray matter of the rat spinal cord.
• The findings validate the use of high-field (9.4T) resting-state fMRI for studying spinal cord functional connectivity in rodents.