Figure 5. Reduced connectivity of ErbB4⁺ PV interneurons in Nrg3 mutants.

• A
  Schematic outline of the connectivity analyses performed in hippocampal slices. PV inhibitory cells (shown in red) were identified using a genetically encoded fluorescence marker (ParvCre;Ai14flox) and recorded from. Neighboring pyramidal neurons were stimulated to probe for connectivity to the recorded interneuron.
• B
  Quantification of the proportion of connected vs. unconnected pyramidal neurons in slices from wildtype (wt) and Nrg3 mutants. Data are presented as bars, and the numbers of connected/tested neuron pairs from 20 wildtype and 30 mutant mice are displayed. Chi‐square test was performed to assess statistical significance (****P < 0.0001).
• C
  Example traces of evoked excitatory postsynaptic currents (eEPSCs) averaged over 50 sweeps.
• D, E
  Quantification of the peak amplitude of the first eEPSC (D) and of the paired pulse ratio (E).
• F–I
  sEPSC recordings from CA1 pyramidal (F, H) and PV neurons (G, I) in acute slices. sEPSC frequencies (F, G) and amplitudes (H, I) are shown.

Data information: (D–E) Data from n = 59 (wt) and n = 55 (Nrg3 ^−/−) neuron pairs from 20 wildtype and 30 Nrg3 ^−/− mutant mice were analyzed using Mann–Whitney U‐test (unpaired, two‐tailed, *P < 0.05). Means ± SD of eEPSC amplitudes shown in (D): wt 24.9 ± 30.4 pA, Nrg3 ^−/− 13.6 ± 16.6 pA. Means ± SD of paired pulse ratio (PPR) shown in (E): wt 0.81 ± 0.47, Nrg3 ^−/− 0.94 ± 0.40. (F–I) Data from n = 17 wildtype and 16 Nrg3 ^−/− pyramidal neurons and n = 17 wildtype and 13 Nrg3 ^−/− PV interneurons recorded in slices of five wildtype and seven Nrg3 ^−/− mice were analyzed using unpaired two‐tailed t‐test (*P < 0.05; ns, not significant). Data in (D–I) are presented as box plots with Tukey's whiskers and outliers; means are indicated as plus symbols.