Robustness of neuronal tuning to binaural sound localization cues against age-related loss of inhibitory synaptic inputs
Fig 6
Simulated effects of inhibition loss on binaural tuning of LSO modeled with a passive IF model.
A-D. Simulated ILD-tuning. E-H. Simulated envelope phase-tuning at 300 Hz. Panels A, B, E and F present simulated binaural ILD- or phase-tuning curves for different numbers of inhibitory inputs either without (A,E) or with (B,F) amplitude compensation. The color code used is the same as in Figs 2–4. Thin lines in C and G show peak (max) and trough (min) rates of the corresponding binaural tuning curves in B and F, respectively. Thick solid lines in C and G show the modulation depth defined as the difference between maximum and minimum rates for the compensated case, while gray dot-dashed lines show that for the uncompensated case. Panel D presents neuronal discriminability of ILD tuning curves averaged over the range between -45 and +15 dB and normalized to the value for 8 inhibitory inputs. Panel H presents the neuronal discriminability of binaural tuning curves averaged over the range between -180 and +180 degrees and normalized to the value for 8 inhibitory inputs. In D and H, solid black lines indicate the compensated case, while gray dash-dotted lines indicate the uncompensated case.