Anticorrelated resting-state functional connectivity in awake rat brain

Area of Science:

• Neuroscience
• Neuroimaging
• Brain Connectivity

Background:

• Resting-state functional connectivity (RSFC) is crucial for understanding brain function and disease.
• Focus on positive RSFC has limited understanding of negative RSFC (anticorrelation).
• Global signal correction, often used in RSFC analysis, can introduce artifactual anticorrelation, obscuring true biological signals.

Purpose of the Study:

• To demonstrate robust, artifact-free negative RSFC in a specific frontolimbic circuit.
• To investigate the preprocessing independence and functional significance of negative RSFC.
• To establish a reliable method for studying anticorrelation in neural circuits.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure RSFC in awake and anesthetized rats.
• The infralimbic cortex (IL) and amygdala circuit was targeted for analysis.
• Data preprocessing methods were varied to assess the robustness of observed anticorrelation.

Main Results:

• Robust, anatomically specific, and reproducible anticorrelated RSFC was observed between the IL and amygdala in awake rats.
• This anticorrelation was independent of global signal correction and other preprocessing steps.
• Anticorrelated RSFC was absent in anesthetized rats, suggesting functional relevance.

Conclusions:

• Negative RSFC can be reliably detected in specific neural circuits, independent of preprocessing artifacts.
• This finding enhances the utility of RSFC for studying neural circuitry and brain networks.
• The study provides a foundation for investigating the neurobiological basis of anticorrelation, particularly in the IL-amygdala circuit.