Fig. 3.

Comparison of bilateral responses to right nVIII (A and C) and left lateral edge stimulation (B and D). A and B: top row shows arrays of average absorbance traces superimposed on the monochrome image of the Cb (as in Fig. 1C). During nVIII stimulation (A) and lateral edge microstimulation (B), diodes along the lateral Cb edges exhibited strong responses. Note the position of the bipolar electrode in left Cb of B. Magnified traces above each array have a color correspond to the diode(s) of the same color in the array. Blue traces are ipsilateral, and red traces are contralateral to the side of stimulation. Note that the red traces are smaller than blue traces, yet have similar latency following the stimulation (arrowhead). C and D: bottom row shows pseudocolor images of the spatial extent of the Cb responses, showing responses near their peak amplitude at the same latency following stimulation. Caudal Cb is up and arrows indicate the rostral and caudal extent of the midline. Cb and nVIII were both stimulated with a 500-Hz train of 5 100-μA pulses. Responses contralateral to the stimulated nVIII are averaged from 6 adjacent diodes stimulated with 5 trains.