Cortical projections to the human red nucleus: a diffusion tensor tractography study with a 1.5-T MRI machine

Area of Science:

• Neuroscience
• Human Anatomy
• Brain Imaging

Background:

• Previous studies in non-human primates indicated sensorimotor and premotor cortical projections to the red nucleus.
• Human brain injury studies suggested associative cortical areas project to the red nucleus.
• Conflicting findings necessitate a re-evaluation of human corticorubral pathways.

Purpose of the Study:

• To investigate in vivo human anatomical projections from the cerebral cortex to the red nucleus.
• To clarify the origin of corticorubral pathways in humans using advanced imaging techniques.

Main Methods:

• Utilized diffusion tensor imaging (DTI) with streamlined axonal tracking.
• Studied connectivity between the cerebral cortex and red nuclei in seven healthy volunteers.
• Performed imaging at 1.5 Tesla field strength.

Main Results:

• Consistently tracked trajectories between the red nuclei and ipsilateral pericentral cortex.
• Identified projections to the prefrontal cortex and temporal cortex.
• Observed connections to the striatum in two subjects, and pathways through the superior cerebellar peduncle and central tegmental tract within the cerebral trunk.

Conclusions:

• The human red nucleus primarily receives afferent connections from the sensorimotor cortex.
• Prefrontal cortical projections to the red nucleus are a significant finding in humans.
• This study provides a clearer map of human corticorubral connectivity.