four treatments have been found to block the sharpening process : ( a ) blocking the activity of the ganglion cells with intraocular tetrodotoxin ( ttx ) , ( b ) rearing in total darkness , ( c ) correlating the activation of all ganglion cells via stroboscopic illumination and ( d ) blocking retinotectal synaptic transmission with alpha-bungarotoxin ( alphabtx ) .
C0228071
ganglion cells
C0017067
ganglion