Cerebro-spinal somatotopic organization uncovered through functional connectivity mapping.

Area of Science:

• Neuroscience
• Human Physiology
• Medical Imaging

Background:

• Somatotopy, the mapping of body parts to the central nervous system (CNS), is crucial for sensorimotor function.
• Previous studies examined brain and spinal cord somatotopy separately, often requiring invasive stimulation.
• The in vivo somatotopic organization of human cerebro-spinal functional connections remained unexplored.

Purpose of the Study:

• To investigate the shared somatotopy between the brain and cervical spinal cord in humans.
• To demonstrate the utility of simultaneous resting-state functional MRI (fMRI) for mapping cerebro-spinal functional connections.
• To establish a non-invasive method for probing large-scale sensorimotor system organization.

Main Methods:

• Simultaneous brain and cervical spinal cord functional magnetic resonance imaging (fMRI) was employed.
• Resting-state functional connectivity analyses were used to identify correlations between spinal cord segments and brain regions.
• A complementary data-driven analysis validated the identified somatotopic organization.

Main Results:

• A somatotopic gradient was revealed within the cortical sensorimotor network based on functional connectivity patterns.
• Distinct brain regions showed preferential correlations with specific spinal cord segments.
• Spinal cord segments were successfully identified by their connectivity profiles with the sensorimotor cortex.

Conclusions:

• Resting-state cerebro-spinal fMRI can effectively probe the large-scale somatotopic organization of the human sensorimotor system.
• This non-invasive approach requires minimal experimental burden.
• Findings hold promise for understanding normal and impaired somatosensory-motor functions.