Ratio of the total charge of pIPSC (pIPSQ) to that of uIPSC (uIPSQ). Each symbol represents the ratio value for a pair of PV → Pyr cells (left column) and of SOM → Pyr cells (right column) obtained from the in vivo cortex. Filled symbol with vertical bar in the right represents means ± SEM. In the left column the value of SEM was very small so that it did not appear outside the symbol. Double asterisks indicate that the difference in the mean between the left and right columns is statistically significant at p < 0.01 (unpaired t-test).