Figure 4. Decreased glutamatergic transmission and increased LTS interneuron excitability in layer V mPFC in NRG1-IV/NSE tTA mice. A, Sample traces and quantification of mEPSCs recorded from layer V pyramidal neurons from WT and NRG1-IV/NSE tTA mice. (n = 4 WT mice, 12 slices, 20 cells and n = 4 NRG1-IV mice, 12 slices, 19 cells). Means were significantly different between genotypes (**p = 0.0029) by unpaired Student's t test. B, Sample traces and quantification of mIPSCs recorded from layer V pyramidal neurons of mPFC in NRG1-IV/NSE tTA mice (n = 3 WT mice, 10 slices, 16 cells and n = 4 NRG1-IV mice, 11 slices, 18 cells). C–F, Repetitive firings were evoked by various depolarizing steps and action potential numbers were plotted against the depolarizing currents injected into neurons in layer V of mPFC. Representative traces are shown on the left and quantifications on the right. C, Pyramidal neuron excitability (n = 4 WT mice, 11 slices, 11 cells and n = 4 NRG1-IV mice, 12 slices, 12 cells). D, LTS neuron excitability. LTS interneurons were characterized by a short burst in the first 2–3 spikes, wider half-width, and smaller fAHP of action potentials with very high input resistances. (n = 4 WT mice, 11 slices, 11 cells and n = 4 NRG1-IV mice, 11 slices, 12 cells). Means were significantly different between genotypes (*p = 0.04), by unpaired Student's t test. E, RS interneuron excitability (n = 3 WT mice, 5 slices, 5 cells and n = 3 NRG1-IV mice, 9 slices, 9 cells). F, FS interneuron excitability (n = 3 WT mice, 8 slices, 8 cells and n = 4 NRG1-IV mice, 12 slices, 12 cells). Normal basal transmission and LTP of the hippocampus in adult NRG1-IV/NSE-tTA mice. G, H, NRG1-IV/NSE-tTA mice display normal LTP. Example fEPSP recordings before (black lines) and 60 min after LTP induction (red lines) are shown in G and the complete time courses are shown in I. Normal paired pulse facilitation (PPF). The ratios of the second and first EPSP slopes were calculated and mean values are plotted against different interpulse intervals (IPIs, 12.5–1600 ms). J, Normal basal synaptic transmission in NRG1-IV/NSE-tTA mice. Input–output curves were generated by plotting the postsynaptic response (amplitude of fEPSP) as a function of the stimulation intensity. Data are shown as means ± SEM.