In the retina, multiple processing steps contribute to the neuronal signals sent to higher visual centers. Retinal ganglion cells (RGCs) are the final output neurons in the retinal pathway; their output is thought to be mainly determined by presynaptic inputs; however, recent evidence suggests that the biophysical properties of RGCs such as the axon initial segment (AIS) also play an important part in signal modulation.Whole-cell patch-clamp experiments were performed to measure the spiking responses of ON-alpha sustained (ON-αs), OFF-alpha sustained (OFF-αs), and OFF-alpha transient (OFF-αt) RGCs in the wild-type mouse retina. Cell types were classified through light stimulation; intrinsic spiking properties were determined by intracellular current injections into the soma.We compared firing rates during 500ms long current injections across the three αRGC types and found significant difference in their maximum sustained firing rates (153/132/107Hz for ON-αs/OFF-αs/OFF-αt RGCs). Furthermore, we found differences in the sustained to peak ratio of firing rates as well as the depolarization level at which action potential generation fails. The duration of action potentials at spiking threshold was longest in ON-αs followed by OFF-αs and OFF-αt RGCs (0.32/0.28/0.22ms).The findings reported here show distinct intrinsic spiking properties across the three types of αRGCs. In general, sustained αRGCs responded more sustained not only to light stimulation but also to current injections. The observed differences may have a significant influence on the conversion of presynaptic inputs into spiking outputs and therefore for signal modulation along the visual pathway.