The sensitivity of AISS phase one and phase two to TTX is different. TTX (100 nM) is puffed onto GABAergic neurons after AISS onset through a pipette containing Alex-488 (green) in the ACSF. Whole-cell recording pipette contains standard pipette solution (Methods) plus Alex-568 (red fluorescent). A) illustrates whole-cell recoding (a red cell) before puffing TTX. B) shows whole-cell recording after puffing (green fluorescent around this cell). C) shows a trace of the evoked spikes induced just before AISS expression (black trace in the first part) as well as AISS under the control (black trace) and TTX application (green and red traces), in which whole-cell recording is under the voltage-clamp. The spike amplitudes are reduced from full spikes to spikelets by using TTX. D) shows the phase-plots for these AISS and spikelet waveforms under the control (black traces) and TTX application (green and red traces). Phase two is completely blocked by TTX (green traces), but phase one is not (reds). E) shows dynamical changes in the rising slopes for phase one (green and red symbols) and phase two (green symbols) after TTX application, in which the colors of symbols corresponds to those of traces in panels C ~ D. Phase two is quickly and completely blocked by TTX, but phase one is not. F) shows the number of evoked spikes before the blockades of phase one (square symbols, n = 5) and phase two (round symbols).