Direct Spleen-Vagus Nerve Communication Uncovered By Platinized Graphene Fiber Electrodes

The spleen is a main organ with vital functions and a main component in the neuroinflammatory reflex. We used a reduced liquid crystalline graphene oxide (rGO, 40 μm diameter) fiber coated with platinum (Pt) as a super-flexible suture-like electrode to use as a handover knot to interface multiple neurovascular plexus (NVP), allowing sensitive recording from four splenic NVPs. The vagus nerve, as the main autonomic nerve and brain-periphery autonomic link, has been suggested as a spleen modulator on the inflammatory reflex. We demonstrate that electrical stimulation of cervical and sub-diaphragmatic vagus nerve, evokes activity in a subset of SN terminal branches, providing evidence for a direct VN control over the spleen. Adenoviral tract-tracing revealing an unconventional direct brain-spleen projection. We propose the high-performance Pt-rGO fiber electrodes, to be used for the fine neural modulation of other small neurovascular plexus at the point of entry of major organs that could be used as a bioelectronic medical alternative.