Cingulo-opercular control network and disused motor circuits joined in standby mode

Area of Science:

• Neuroscience
• Systems Neuroscience
• Cognitive Neuroscience

Background:

• The brain's functional connectivity (FC) adapts to changes in motor activity.
• Understanding how neural networks reorganize during periods of disuse is crucial for rehabilitation and recovery.

Purpose of the Study:

• To investigate the impact of short-term upper-limb immobilization on whole-brain functional connectivity.
• To identify specific brain networks affected by disuse and the underlying mechanisms of change.

Main Methods:

• Whole-brain resting-state functional MRI (rs-fMRI) was employed in participants with a 2-week upper-limb cast.
• Functional connectivity analyses were performed to assess changes in network interactions.
• Censoring and modeling techniques were used to examine spontaneous activity patterns.

Main Results:

• Disused motor regions showed increased functional connectivity specifically with the cingulo-opercular network (CON).
• These connectivity increases were confined to the CON and somatomotor networks, sparing others like the salience and default mode networks.
• Spontaneous activity pulses in disused motor regions and CON control areas mediated the observed FC increases.

Conclusions:

• Upper-limb casting induces a 'standby mode' in disused motor circuits.
• This standby mode is characterized by spontaneous activity pulses and enhanced connectivity to CON executive control regions.
• These findings provide insights into neural plasticity during motor disuse and potential targets for intervention.