Fig. 1: Experimental design.

a Neural tracers were injected into the peroneal and tibial fascicles of the rat sciatic nerve 48 h before the EIT experiment. b EIT recordings and image reconstruction. Left: peroneal (red), tibial (green), and sural (gray) fascicles were electrically stimulated with bipolar electrodes placed 1–1.5 cm distally from the EIT cuff. Middle: diagram showing the 4-off electrode spacing configuration in the 14-electrode cuff forming a full ring around the rat common sciatic nerve; example of multiple δV traces from an experimental EIT recording. Right: Exemplar cross-sectional localization of the recorded fascicular activity from tibial (T), peroneal (P), and sural (S) fascicles at the level of the common sciatic nerve. The range of values for every image was normalized between 0 and 1 and the rainbow color scale indicates the top 50% of color for each image, i.e., full width at half maximum (FWHM) intensity scaling. c After the EIT experiment, the nerve was scanned with microCT. d Fluorescent microscopy of histological sections. In this exemplar section, tibial fascicle is labeled with fluorescent Dextran-Alexa 488 (green) and peroneal fascicle with Dextran-Alexa 555 (red); sural fascicle is not labeled. e Cross-validation of EIT images of impedance changes in individual fascicles against microCT and histological sections.