Structural Connectivity Between the Retrosplenial Cortex and Hippocampus in the Healthy Human Brain: A Diffusion Tensor Tractography Study.

The retrosplenial cortex (RSC) and hippocampus are important regions involved in spatial navigation by integrating vestibular information into spatial representations. Although functional interactions between these regions have been demonstrated, there is currently a lack of evidence regarding the structural connectivity between the RSC and hippocampus in the human brain. This study aimed to reconstruct and characterize a tractography-derived pathway between the RSC and hippocampus in healthy adults using diffusion tensor imaging (DTI) tractography. Methods Thirty healthy adults were recruited. The seed region of interest (ROI) was defined in the RSC with reference to both sagittal and axial planes, and the target ROI was placed within the hippocampus on the axial plane. The structural characteristics, including fractional anisotropy, mean diffusivity, and tract volume were analyzed. Results A tractography-derived RSC-hippocampal pathway was identified bilaterally in all participants. Conclusion This study characterized a tractography-derived RSC-hippocampal pathway in the healthy human brain. Our findings provide insight into RSC-hippocampal structural connectivity and suggest a potential structural substrate for interactions between these regions in spatial information processing.