Population IPSC (pIPSC) evoked by photoactivation of a mass of PV or SOM neurons. (a,b) pIPSCs recorded from the same neurons as in Fig. 1a and b, respectively, so that the traces are superimposed with the uIPSCs shown in Fig. 1 at the slower time scale. (c–f) Peak amplitude, rising slope, decay tau and total charge of pIPSCs of 12 Pyr cells evoked by the photoactivation of PV neurons (left) and those of another 11 Pyr cells evoked by the photoactivation of SOM neurons (right). Double and single asterisks indicate that the difference in the mean between the left and right columns is statistically significant at p < 0.01 and p < 0.05, respectively (unpaired t-test).