Figure 6 of Gao, Mol Vis 2016; 22:387-400.

Figure 6. Representative traces of membrane potential in current-clamp mode. Spontaneous action potentials recorded from primary cultured RGCs purified by TIP and TIPM method at the second to the fourth day. No current injection was applied. Membrane potential was current-clamped at around -55 mV (A). In some cells action potentials were not produced spontaneously, indicating these were not RGCs (B).