The vestibulo-hippocampal pathway in the healthy human brain: anatomical study using the diffusion tensor imaging

Abstract

Introduction: Spatial orientation is the ability to perceive changes in head position and movement, and is associated with vestibular system and hippocampus. Although the projection from the vestibular nucleus to the hippocampus is associated with spatial perception, there is currently a lack of evidence regarding direct pathway projecting from vestibular nuclei to the hippocampus. Therefore, this study investigated the anatomical characteristics of the vestibulo-hippocampal pathway (VHT) in a normal human brain using diffusion tensor imaging (DTI) tractography.

Methods: Thirty healthy adults (n = 30) were recruited. The seed region of interest (ROI) was placed on the vestibular nuclei at the pons levels, and the target ROI was assigned at hippocampus in the axial plane. Fractional anisotropy, mean diffusivity, and tract volume of the VHT were analyzed.

Results: The VHT originated from the medial and lateral vestibular nuclei at the pons level and terminated at the hippocampus. The VHT passed through the tegmental area at the midbrain level and thalamus and finally projected to the hippocampus.

Conclusions: This study identified that VHT originated from the vestibular nuclei in pons and terminated at the hippocampus via tegmental area and thalamus. Therefore, our findings provide an understanding of the vestibular-hippocampal interactions.

Keywords: Spatial orientation; diffusion tensor imaging; hippocampus; perception; vestibulo-hippocampal pathway.