Table 1.

Values for the parameters used in the SAC model

Parameters	Symbol	Value	Conditions
Internal resistance	Ri	0.4 MΩ	Small axial internal resistance (Fig. 3C)
		40 MΩ	Large axial internal resistance (Fig. 3D)
		4 MΩ	All other conditions
Potassium channels equilibrium potential	EK	–95 mV	All conditions
Glutamate channels equilibrium potential	EGL	0 mV	All conditions
GABA channels equilibrium potential	EGA	−57.3 mV	In all segments (Fig. 4A)
		−37 mV	In all segments (Fig. 4B) Figs 4C and D, 5 and 6
		From −37 mV in soma to −77 mV in the most distal dendritic segments
Resistance of potassium channels*	RK	177.6 GΩ	All conditions (dendritic segments)
		888 GΩ	All conditions (soma)
Resistance of glutamate-gated channels*	RGL	266.7 GΩ	In dark (dendritic segments)
		8.0 GΩ	In light (dendritic segments)
		1330 MΩ	In light and dark (soma)
Resistance of GABA-gated channels*	RGA	320 GΩ	In dark (dendritic segments)
		9.6 GΩ	In light (dendritic segments)
		1600 MΩ	In light and dark (soma)
Width of SAC		400 μm	All conditions
Width of dendritic segment		2 μm	All conditions
Width of simulated moving bar of light		54 μm	All conditions
Speed of simulated moving bar of light		500 μm s−1	All conditions

^*Values derived from measurements of the input resistance of starburst amacrine cells in the presence and absence of GABA_A receptor blockade (see text for details).