Figure 6. Measurements of the latencies of EPSCs and APs are consistent with the idea that fMP cells, driven by SL cells, provide feedback synaptic inhibition. A, Left, APs elicited by minimal stimulation of the LOT, measured in an SL cell (black trace) and an SP cell (gray trace). Right, Histograms of latencies between the time of the stimulus and the peak of the AP (arrowed in left-hand panel; combined measurements from n = 4 SL cells and n = 4 SP cells). Redrawn from Suzuki and Bekkers (2011). B, Left, Two EPSCs elicited by minimal LOT stimulation, recorded in an fMP cell. Stimulus artifacts have been clipped. Right, Histogram of latencies from the stimulus time to the foot of the EPSC (arrowed in left-hand panel; combined measurements from n = 10 fMP cells). C, Left, Two APs elicited by minimal LOT stimulation, measured in an fMP cell. C, Right, Histogram of latencies from the stimulus time to the AP peak (arrowed in left-hand panel), shown as an unbroken line (combined measurements from n = 8 fMP cells). Also shown (red dashed line) is the histogram of latencies of IPSCs responsible for feedback inhibition, measured from tissue-cut experiments like those in Figure 4C, right (combined measurements from n = 13 cells).