Table 1.

Regularity of several on- and off-centre types of retinal cells

Regularity index
Cell typeReferenceOn/offOn+offOnOff
Cat α RGC Wässle et al., 1981a 0.832.44.54.7
Cat β RGC Wässle et al., 1981b 0.922.75.35.3
Rabbit cholinergic AC Diggle, 1986 1.072.83.53.9
• On/off is defined here as the number of on-centre cells divided by the number of off-centre cells. The regularity index of α and β retinal ganglion cell (RGC) mosaics were taken from the references. The regularity indexes for the cholinergic amacrine cells (AC) of the rabbit were not reported by Diggle (Diggle, 1986), and so were calculated for the current study. Cell count ratios and regularity indexes from Jeyarasasingam et al. (Jeyarasasingam et al., 1998) were not given, although their paper suggests the regularity of either on- and off-centre α RGCs in adult cat is around 4.0.