Figure 6.
Ventral hippocampal inputs preferentially activate PV+ interneurons. A, Whole-cell current-clamp recordings of vHPC-evoked EPSPs and spikes in a pair of D1+ and PV+ cells from resting membrane potentials, in the presence of CPP, gabazine, and the GABABR antagonist CGP. Triangles indicate light pulses. B, Probability of evoked spiking in D1+ and PV+ cells across a range of light durations, shown as means ± SEM. C, Latency to spike, measured from light onset to peak of AP, for D1+ and PV+ cells with 4 ms LED duration. D, Similar to A for a spontaneously spiking SOM+ interneuron. E, Spike raster plot for an example pair of D1+ and SOM+ cells, highlighting impact of vHPC inputs (blue line) on spike timing, with the inset showing expanded time around stimulation. F, Similar to B, showing probability of evoked spiking in D1+ and SOM+ cells, calculated during a 10 ms window after light stimulation, with baseline firing rate subtracted. G, Similar to C for D1+ and SOM+ cells. H–J, Similar to D–F, but in the absence of gabazine to allow for local inhibition. K, Baseline firing rate in SOM+ interneurons, with gabazine (+GZ) or without gabazine (−GZ), shown as means ± SEM. **p < 0.01; ***p < 0.001.