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. 2008 Apr 3;586(Pt 10):2551–2580. doi: 10.1113/jphysiol.2008.150755

Figure 9. Effect of TTX on rod-, mixed rod + cone-, and cone-driven ERGs.

Figure 9

A, amplitudes of the cone-isolated ERGs (group mean ± s.e.m.) plotted as a function of stimulus energy before (black circles) and after (white circles) TTX injection for the dark-adapted condition and backgrounds of −0.7, 0.3 and 2.3 log sc td (top to bottom). Responses were measured at 50 ms after the flash in all cases. The continuous black and dashed black curves represent hyperbolic saturation functions fitted to the ERG amplitudes before and after TTX, respectively. B, ERG amplitudes of mixed rod–cone ERGs for the same eyes as in A and a subset of the data in Fig. 4 (group mean ± s.e.m.) plotted as a function of stimulus energy before (black circles) and after (white circles) TTX injection, for the dark-adapted condition and backgrounds of −0.7, 0.3 and 2.3 log sc td (top to bottom). Grey circles represent the cone-isolated ERG amplitudes for the same animals before TTX. All responses were measured at 50 ms after the flash. The vertical dotted line represents flash energy that produces 10 μV of the maximum cone-isolated ERG amplitude for each background, except the photopic one. C, TTX-sensitive (before TTX – after TTX) ERG amplitudes, measured at 50 ms (group mean ± s.e.m.) for the mixed rod + cone ERG (black bars) compared to those for the cone-isolated ERG (white bars), for flash energies of 1 log sc td (left) and 1.6 log sc td (right). * TTX-sensitive amplitudes significantly different from the others (t test; P < 0.05).