Figure 2

<p> <i>The capacity of human neural progenitors to preserve retinal function is augmented by GDNF expression.</i> ERG response amplitudes to full field light stimulation were recorded at approximately P100 in RCS rats injected with hNPC^ctx–GDNF (<i>n</i> = 9), hNPC^ctx (<i>n</i> = 21) or medium alone (<i>n</i> = 3) into the subretinal space. Individual components of the ERG waveform (a-wave, composite b-wave, cone b-wave and rod b-wave) reveal relative contributions of different retinal cells to the overall functional activity of the retina. Cone b-waves were delineated by a double flash protocol and the rod-attributable b-wave was derived by subtraction from the composite level. Eyes injected with hNPC^ctx–GDNF demonstrated significantly greater a-wave and cone b-wave amplitudes than those receiving hNPC^ctx (*<i>p</i><0.05; **<i>p</i><0.01; Student's unpaired <i>t</i>-test). In contrast, the composite b-wave and rod b-wave amplitudes were not statistically different between the two groups. Control eyes injected with medium alone (sham-operated eyes) had no recordable ERG waves and are not included in the graph. Data are expressed as mean ± SEM.