Figure 3

Selectivity as a function of stimulation amplitude. Grids of blue traces show 500 ms post-stimulation recordings from 32 MEA channels, with red horizontal lines representing the threshold for detecting an evoked response. Traces with red shading include a response evoked by stimulation from cuff pair 1–2. Traces with blue shading include a response evoked by stimulation from cuff pair 3–4. Grids of red, blue, and purple squares show the pattern of recruitment and overlap in responses at various stimulation amplitudes. Red, blue, and purple squares represent MEA channels with responses evoked by only cuff pair 1–2, only cuff pair 3–4, or both cuff pairs, respectively. In this example from a single animal, as stimulation amplitude increases from 400 to 580 µA for bipolar cuff pair 1–2, the number of selectively responding MEA channels increases from one to fifteen. Similarly, as stimulation amplitude increases from 400 to 460 µA for bipolar cuff pair 3–4, the number of selectively responding MEA channels increases from one to three. Additionally, as stimulation amplitude increases, the number of MEA channels responding to both bipolar cuff pairs increases from one to four. The orientation of channels in the figure is from caudal to rostral, left to right, on the ventral side of the nodose ganglia.