Figure 7: Electrophysiological characterization of LEC cells projecting to newborn GCs.

(a) Photomicrograph showing MCh⁺-putative multipolar neurons in LEC layer II. Nuclei are labelled with DAPI (blue). Scale bar, 50 μm. (b) Schematic representation of the location of MCh⁺-recorded cells; different types of cells are represented by the respective colours in (c–g) Representative traces of membrane potential changes in response to current injection of a putative stellate cell (c; Type I), pyramidal cell (d; Type II), multipolar cell (e; Type III) and two different types of cells with irregular firing differentiated by sag presence (f and g; Type IV and V, respectively). Prominent sag (onset indicated by asterisk) was present in some cell types at hyperpolarization. Depolarizing steps were delivered to threshold and twice-threshold current. Scale 10 mV, 50 ms. Insets show enlarged spike after-potentials. Scale: 5 mV, 5 ms. (h) Differential firing frequency in response to increasing current steps of the different types of cells. (i) Number of spikes elicited at different current steps. Type I, n=2 (green), Type II, n=2 (red), Type III, n=6 (blue), Type IV, n=3 (purple) and Type V, n=2 (orange). Data are means±s.e.m.