Figure 2.

Electrophysiological properties of AOB IGCs. A, Morphologic reconstruction of an IGC dendritic arbor. B1–D1, Responses of three representative IGCs (top) to current clamp challenges (bottom). Scale bars: 10 mV, 500 ms. Inset in B1 shows the blockade of the hyperpolarization-activated depolarizing I_H sag potential by ZD7288 (10 µM). B2–D2, Responses of the same three IGCs (top) to a series of command potential steps from –70 mV in voltage clamp (bottom). Hyperpolarizing responses were also recorded, but are not shown. Scale bars: 500 pA, 100 ms. E, Spike rate input-output curves for IGCs subjected to a series of step depolarizations in current clamp. Dashed green line indicates the mean ± SE (N = 52). F, Spike accommodation index for IGCs subjected to the same series of step depolarizations shown in C (N = 52). G, Maximal I_H sag potential for 52 IGCs. H, Input-output curves for peak inward voltage-gated Na⁺ currents (N = 51). I, Input-output curves for the ratio of peak voltage-gated Na⁺ to peak voltage-gated K⁺ currents (N = 52). J, Input-output curve for normalized voltage-gated K⁺ current inactivation (N = 52). K, Representative recordings of spontaneous synaptic currents (command potential –70 mV) before and during blockade of GABA_A receptors with gabazine (2.5 µM), AMPA and NMDA receptors (10 µM AP5, 1 µM NBQX), and Type I/II mGluRs (100 µM MCPG, N = 15). L, Blockade of net spontaneous synaptic currents during pharmacological blockade (holding potential –70 mV). Asterisks indicate p < 0.05 by multiple comparisons of mean ranks, Kruskal–Wallis test. M, sEPSC frequency (N = 52). N, sEPSC amplitude (N = 52).