Fig. 2

Location and directional tuning of identified commissural neurons receiving utricular input. (A) Coronal projection of reconstructions of 31 commissural neurons that receive direct utricular afferent input, colorized by their inferred directional tuning [see color code, (D)]. In addition, the left and right Mauthner cells are shown in gray to facilitate comparisons with other results. Note that the Mauthner cells are shown as spheres. Nearly all commissural utricular neurons follow a similar axon projection path. (B) Sagittal view of the same neuron reconstructions as in (A). Most of these commissural neurons are located caudally to the Mauthner cell bodies. (C) Horizontal view of the same neurons as in (A). Arrow points to a position where several commissural utricular axons can be seen to turn rostrally, in the same mediolateral position as the Mauthner cell body. Asterisk indicates the presumed tangential neuron described in text. Scale bar applies to (A–C). (D) Summary of the inferred directional tuning of commissural utricular neurons. Vector direction indicates the computed directional tuning of each neuron. Arrow lengths have been adjusted to facilitate visualization.