Sledge runner fasciculus: anatomic architecture and tractographic morphology.

Area of Science:

• Neuroanatomy
• Human Connectomics
• Diffusion Tensor Imaging (DTI)

Background:

• The sledge runner fasciculus (SRF) is a recently identified occipital lobe fiber tract.
• Its precise anatomical and tractographic morphology remains largely uncharacterized.
• The SRF is hypothesized to be involved in spatial navigation and visuospatial imagery.

Purpose of the Study:

• To investigate the detailed anatomy and axonal connectivity of the sledge runner fasciculus (SRF).
• To delineate the SRF's topography in relation to adjacent white matter pathways.
• To provide detailed anatomo-imaging evidence of this newly discovered fiber tract.

Main Methods:

• Cadaveric dissections using fiber microdissection technique on 20 hemispheres.
• Diffusion Tensor Imaging (DTI) analysis on 35 healthy participants from the Human Connectome Project dataset.
• Tailored DTI protocol to investigate SRF structural architecture.

Main Results:

• The SRF was identified as a discrete fiber pathway in the medial occipital lobe with a dorsomedial-ventrolateral trajectory.
• It connects the anterior cuneus, anterior lingula, isthmus of the cingulum, and posterior parahippocampal gyrus.
• Dissection and DTI findings showed strong correspondence in SRF topography, morphology, and connectivity.

Conclusions:

• The study supports the hypothesis that the SRF is integral to the structural connectivity of brain regions involved in spatial navigation and visuospatial imagery.
• Detailed anatomical and imaging data on the SRF's microarchitecture have been provided.
• This research enhances understanding of the human brain's white matter organization.