Based on the phase of their response to 0.3 Hz sinusoidal rotations, axons in the posterior ampullary nerve can be distinguished into two groups: low phase group (≤91°, dashed outline, n = 552) and high phase group (≥104°, solid outline, n = 33). Intra-axonally labeled fibers traced to the posterior crista (PC) fell into the low-phase group (light shading, n = 54), whereas labeled fibers traced to the papilla neglecta (PN) fell into the high-phase group (n = 4, dark shading).