AB147. SOH24AB_186. Demonstration of a direct, structural connection linking the intestine and brain in the human setting: the vagus

Background: Whilst the occurrence of a gut-brain axis is generally accepted, a structural connection directly linking the intestine and brain has yet to be demonstrated in the human setting. The aim of the current study was to combine recent advances in abdominal anatomy, with digital techniques, to reconstruct the vagus nerve (a component of the gut-brain axis) along the entirety of its course.

Methods: The Visible Korean Project (VKP) dataset includes 4,500 images of axial sections (taken every 0.3 mm) of a male human. The dataset was imported into Horos(c) and the vagus nerve was segmented from brainstem to intestinal level. Segmentations were combined to generate a 3D digital surface model of the vagus. To determine the relations of the vagus, models of the mesenteric domain, mesentery, intestine and abdominal lymphatics, were generated. All models were processed in Cinema 4D, and assembled to generate a complete depiction of the vagus.

Results: The vagus nerve directly connects the intestine with the brainstem. Within the abdomen, the nerve was located entirely in the mesentery, and thus in the mesenteric domain. The abdominal component of the vagus was co-located with extensive lymphadenopathy. The vagus branched extensively in the abdomen. Branching was not apparent in the thorax.

Conclusions: This is the first study to demonstrate a direct anatomical connection between the intestine and the brain, in the human setting. It thus confirms the occurrence of a structural gut/brain axis in the human setting. The findings have considerable implications for our understanding of the gut-brain axis.

Keywords: Vagus; gut-brain axis; mesentery; Visible Human Project; Dicom